This paper depicts a wideband circularly polarized (CP) antenna for 5G devices. The antenna array has a 3D structure including four simple printed dipole elements with directional radiations, high gain, and high efficiency. It achieves a CP by using the sequential rotation (SR) feeding based on 90°-3dB hybrid couplers in the proposed feeding network. The antenna array bandwidth is wide, 26.7%, with an operating frequency band from 3.35 GHz to 4.35 GHz. The antenna achieves a high peak gain of 10.73 dBi and high efficiency of 93.75%. Besides, the antenna gain is stable over the operating bandwidth (BW). At the centre operating frequency of 3.75 GHz, the angle of circular polarization is 51°. The antenna is designed and fabricated on the Rogers 4003 C substrate. The measured S11 is well matching with the simulation results. With the above characteristics, the proposed antenna can be a suitable candidate for 5G devices.
Outage performance users located outside D2D coverage area in downlink cellul...journalBEEI
Device-to-device (D2D) communication has been proposed to employ the proximity between two devices to enhance the overall spectrum utilization of a crowded cellular network. With the help of geometric probability tools, this framework considers the performance of cellular users under spatial separation with the D2D pair is investigated. The measurement results and analytical expression of outage probability show that the proposed frameworks improve the outage performance at a high signal-tonoise ratio (SNR) at the base station. Results also interpret that the distances between nodes in the D2D-assisted network make slight impacts on the performance of the cellular user.
Design and analysis of microstrip antenna with zig-zag feeder for wireless co...journalBEEI
This paper is presented a microstrip antenna with a zig-zag feeder for wireless communication, it has a wideband frequency spectrum (2-14) GHz. The proposed antenna is designed with a zig zag feed line which gave a wideband frequency and acceptable gain (7.448-5.928) dB, this antenna has zig zag slots printed in the ground plane on a lower side of the dielectric substrate, a certain form tuning stub is used to increase the matching between the feeder in the top layer of the substrate and ground plane in the bottom, this stub has an elliptical slot to performance matching input impedance with the feed line. The feeding technique used to feed this antenna is a strip feed line of 50 Ω. Different types of techniques are used to enhance the bandwidth of this antenna to get a wideband suitable for the requirements of the UWB antenna such as adjust the feed point position of the feed line with a tuning stub. All the radiation properties of the presented antenna are tested such as bandwidth, radiation pattern, and, gain.
Performance analysis of beam divergence propagation through rainwater and sno...journalBEEI
In the present work the future communication requirements need to fulfill with high data rate, FSO (free space optic) with it is tremendous potential is the solution. This research observed the effectiveness analysis of FSO systems by modifying one of the most important FSO parameters beam divergence, under the most affected weather attenuating condition Rainwater and snow pack. The simulation is obtained and analyzed under single channels CSRZ-FSO (carrier-suppressed return-to-zero/free space optical) systems having capacity of 40 Gbps between two transceivers with variable distance. The connection is presently under 5 meteorological turbulences (light rain, medium rain, wet snow, heavy rain and dry snow). The results show the heavy rain and dry snow have a very high attenuation carried out in terms of Q-factor. this result led us to conclude that small divergence offers significant performance improvement for FSO link and this performance decrease every time the beam divergence increase, Therefore, to build inexpensive and reliable transmission media, we go with new method that still in the experiment area called hybrid RF/FSO (radio frequency/free space optical) that compatible with atmospherically status.
A new look on CSI imperfection in downlink NOMA systemsjournalBEEI
Observing that cooperative scheme benefits to non-orthogonal multiple access (NOMA) systems, we focus on system performance analysis of downlink. However, spectrum efficiency is still high priority to be addressed in existing systems and hence this paper presents full-duplex enabling in NOMA systems. Other challenge needs be considered related to channel state information (CSI). In particular, we derive closedform expressions of outage probability for such NOMA systems under the presence of CSI imperfection. Furthermore, to fully exploit practical environment, we provide system model associated with Nakagami-m fading. The Monte-Carlo simulations are conducted to verify the exactness of considered systems.
Simulation and optimization of a tuneable rectangular microstrip patch antenn...TELKOMNIKA JOURNAL
In this paper, a tuneable rectangular microstrip patch antenna (MPA) is simulated and optimized to operate in four frequency bands of the next generation of wireless communication systems. The proposed design incorporates a copper radiating patch with four implanted graphene strips for tuning purposes. The reconfigurable surface impedance of graphene can easily be altered by applying a DC voltage bias directly to the graphene strips, allowing the operating frequency of the antenna to be tuned as desired. The capability of the applied voltage to tune the operating frequency band of the proposed antenna is studied via computer simulation technology (CST) microwave studio (MWS). Frequency selective surfaces (FSSs) are introduced in order to improve the radiation parameters of the antenna. The operating frequency band of the tuneable rectangular MPA increases directly as the applied DC voltage bias is increased. Based on the simulation results, a tuneable rectangular MPA placed between two FSSs is proposed for fifth-generation applications.
Wideband frequency reconfigurable metamaterial antenna design with double H s...journalBEEI
This paper presents the design of wideband frequency reconfigurable metamaterial antenna with double H slots. The design is based on the idea of composite right/left-handed transmission line (CRLH-TL) technique. Bandwidth enhancement was achieved by utilizing series left-handed capacitor CL transmission line parameter. The design has several outstanding advantages which include efficient bandwidth to cover many lower Application bands with multi frequency operation characteristics. A comprehensive analysis and simulation were done by using computer simulation technology (CST) software to determine the performance and efficiency of the proposed antenna. From the result obtained, the antenna aquired bandwidth range which covered (2.3-5.2) GHz which is equivalent to 77% fractional bandwidth. The wideband antenna was reconfigured by using frequency reconfiguration technique. From the reconfiguration results, the antenna can be switch from wideband to two single bands which resonate at 2.4 GHz and 4.2 GHz and to dual band which resonate at 2.4 GHz and 4.2 GHz. The realized peak gain at 2.4 GHz is 2.28 dBi and 2.58 dBi for E and H field respectively. The maximum efficiency of 96% was obtained. The antenna can be use for WLAN, proposed lower 5G band and cognitive radio system for frequency sencing.
A compact triband microstrip antenna utilizing hexagonal CSRR for wireless co...journalBEEI
In this paper, a compact triband printed antenna with hexagonal complementary split-ring resonators (CSRRs) for 4G applications is proposed. The proposed multiband antenna is comprised of a rectangular patch antenna on the top plane, while on the ground plane, hexagonal CSRRs are etched for size miniaturization (at the lower bands) and multiband generation. Another effect of the CSRR is the shifting of the initial resonance of the patch antenna from 5.17 GHz to the higher band of 6.18 GHz. The triband of 180 MHz 2.4~2.59, 150 MHz 2.79~2.94 and 420 MHz 6.04~6.46 GHz bands acquired can cover WLAN/Wi-Fi and WiMAX operating bands adequately. This can be achieved by choosing the optimal size and position of the CSRR on the ground plane carefully. The design occupies a total size of 45 x 45 mm2 using the low-cost FR-4 substrate. Good agreements are obtained between the measured results and the simulated, which are discussed and presented.
Outage performance users located outside D2D coverage area in downlink cellul...journalBEEI
Device-to-device (D2D) communication has been proposed to employ the proximity between two devices to enhance the overall spectrum utilization of a crowded cellular network. With the help of geometric probability tools, this framework considers the performance of cellular users under spatial separation with the D2D pair is investigated. The measurement results and analytical expression of outage probability show that the proposed frameworks improve the outage performance at a high signal-tonoise ratio (SNR) at the base station. Results also interpret that the distances between nodes in the D2D-assisted network make slight impacts on the performance of the cellular user.
Design and analysis of microstrip antenna with zig-zag feeder for wireless co...journalBEEI
This paper is presented a microstrip antenna with a zig-zag feeder for wireless communication, it has a wideband frequency spectrum (2-14) GHz. The proposed antenna is designed with a zig zag feed line which gave a wideband frequency and acceptable gain (7.448-5.928) dB, this antenna has zig zag slots printed in the ground plane on a lower side of the dielectric substrate, a certain form tuning stub is used to increase the matching between the feeder in the top layer of the substrate and ground plane in the bottom, this stub has an elliptical slot to performance matching input impedance with the feed line. The feeding technique used to feed this antenna is a strip feed line of 50 Ω. Different types of techniques are used to enhance the bandwidth of this antenna to get a wideband suitable for the requirements of the UWB antenna such as adjust the feed point position of the feed line with a tuning stub. All the radiation properties of the presented antenna are tested such as bandwidth, radiation pattern, and, gain.
Performance analysis of beam divergence propagation through rainwater and sno...journalBEEI
In the present work the future communication requirements need to fulfill with high data rate, FSO (free space optic) with it is tremendous potential is the solution. This research observed the effectiveness analysis of FSO systems by modifying one of the most important FSO parameters beam divergence, under the most affected weather attenuating condition Rainwater and snow pack. The simulation is obtained and analyzed under single channels CSRZ-FSO (carrier-suppressed return-to-zero/free space optical) systems having capacity of 40 Gbps between two transceivers with variable distance. The connection is presently under 5 meteorological turbulences (light rain, medium rain, wet snow, heavy rain and dry snow). The results show the heavy rain and dry snow have a very high attenuation carried out in terms of Q-factor. this result led us to conclude that small divergence offers significant performance improvement for FSO link and this performance decrease every time the beam divergence increase, Therefore, to build inexpensive and reliable transmission media, we go with new method that still in the experiment area called hybrid RF/FSO (radio frequency/free space optical) that compatible with atmospherically status.
A new look on CSI imperfection in downlink NOMA systemsjournalBEEI
Observing that cooperative scheme benefits to non-orthogonal multiple access (NOMA) systems, we focus on system performance analysis of downlink. However, spectrum efficiency is still high priority to be addressed in existing systems and hence this paper presents full-duplex enabling in NOMA systems. Other challenge needs be considered related to channel state information (CSI). In particular, we derive closedform expressions of outage probability for such NOMA systems under the presence of CSI imperfection. Furthermore, to fully exploit practical environment, we provide system model associated with Nakagami-m fading. The Monte-Carlo simulations are conducted to verify the exactness of considered systems.
Simulation and optimization of a tuneable rectangular microstrip patch antenn...TELKOMNIKA JOURNAL
In this paper, a tuneable rectangular microstrip patch antenna (MPA) is simulated and optimized to operate in four frequency bands of the next generation of wireless communication systems. The proposed design incorporates a copper radiating patch with four implanted graphene strips for tuning purposes. The reconfigurable surface impedance of graphene can easily be altered by applying a DC voltage bias directly to the graphene strips, allowing the operating frequency of the antenna to be tuned as desired. The capability of the applied voltage to tune the operating frequency band of the proposed antenna is studied via computer simulation technology (CST) microwave studio (MWS). Frequency selective surfaces (FSSs) are introduced in order to improve the radiation parameters of the antenna. The operating frequency band of the tuneable rectangular MPA increases directly as the applied DC voltage bias is increased. Based on the simulation results, a tuneable rectangular MPA placed between two FSSs is proposed for fifth-generation applications.
Wideband frequency reconfigurable metamaterial antenna design with double H s...journalBEEI
This paper presents the design of wideband frequency reconfigurable metamaterial antenna with double H slots. The design is based on the idea of composite right/left-handed transmission line (CRLH-TL) technique. Bandwidth enhancement was achieved by utilizing series left-handed capacitor CL transmission line parameter. The design has several outstanding advantages which include efficient bandwidth to cover many lower Application bands with multi frequency operation characteristics. A comprehensive analysis and simulation were done by using computer simulation technology (CST) software to determine the performance and efficiency of the proposed antenna. From the result obtained, the antenna aquired bandwidth range which covered (2.3-5.2) GHz which is equivalent to 77% fractional bandwidth. The wideband antenna was reconfigured by using frequency reconfiguration technique. From the reconfiguration results, the antenna can be switch from wideband to two single bands which resonate at 2.4 GHz and 4.2 GHz and to dual band which resonate at 2.4 GHz and 4.2 GHz. The realized peak gain at 2.4 GHz is 2.28 dBi and 2.58 dBi for E and H field respectively. The maximum efficiency of 96% was obtained. The antenna can be use for WLAN, proposed lower 5G band and cognitive radio system for frequency sencing.
A compact triband microstrip antenna utilizing hexagonal CSRR for wireless co...journalBEEI
In this paper, a compact triband printed antenna with hexagonal complementary split-ring resonators (CSRRs) for 4G applications is proposed. The proposed multiband antenna is comprised of a rectangular patch antenna on the top plane, while on the ground plane, hexagonal CSRRs are etched for size miniaturization (at the lower bands) and multiband generation. Another effect of the CSRR is the shifting of the initial resonance of the patch antenna from 5.17 GHz to the higher band of 6.18 GHz. The triband of 180 MHz 2.4~2.59, 150 MHz 2.79~2.94 and 420 MHz 6.04~6.46 GHz bands acquired can cover WLAN/Wi-Fi and WiMAX operating bands adequately. This can be achieved by choosing the optimal size and position of the CSRR on the ground plane carefully. The design occupies a total size of 45 x 45 mm2 using the low-cost FR-4 substrate. Good agreements are obtained between the measured results and the simulated, which are discussed and presented.
Gain enhancement of microstrip patch antenna using artificial magnetic conductorjournalBEEI
The paper presents an artificial magnetic conductor (AMC) structure to enhance the gain of the double microstrip patch antenna. By placing this kind of metamaterial in between the two Rogers RT5880 substrates, the antenna achieved lots of improvement especially in terms of size miniaturization, bandwidth, return loss, gain and efficiency. The antenna is intended to operate at 16 GHz where the prospect fifth generation (5G) spectrum might be located. Integration of AMC structure into the proposed antenna helps to improve nearly 16.3% of gain and almost 23.6% of size reduction.
Designing large-scale antenna array using sub-arrayjournalBEEI
Antenna array of large scale have been examined for different applications including 5G technology. To get better data rate or a reliable link substantial number of antenna arrays have been utilized to provide high multiplexing gains as well as array gains with high directivity. In this paper a simple but efficient implementation technique of using sub-arrays for the improvement of large-sized uniform arrays. By repeating a small sub-array multiple times large arrays can be designed. This implication of utilizing small array simplifies the design of a larger array which allows the designer to concentrate on the smaller sub-array before assembling larger arrays. So, by investigating the sub arrays the performance and radiation characteristics of large arrays can be anticipated. The array-factor for a planar sub-array of 2x2 (4 elements) is analyzed using Mat-lab software and then a large array is formed by placing the 2x2 sub-array indifferent configurations in a rectangular arrangements up to 8x8 planar array. And then the results are validated with CST (Computer simulation technology) simulation results.In this way the array-factors, directivities, HPBWs, and side lobes of the constructed large arrays are analyzed and associated with the small sub-array.
Simulation and optimization of tuneable microstrip patch antenna for fifth-ge...IJECEIAES
Microstrip patch antennas (MPAs) are known largely for their versatility in terms of feasible geometries, making them applicable in many distinct circumstances. In this paper, a graphene-based tuneable single/array rectangular microstrip patch antenna (MPA) utilizing an inset feed technique designed to function in multiple frequency bands are used in a fifth-generation (5G) wireless communications system. The tuneable antenna is used to eliminate the difficulties caused by the narrow bandwidths typically associated with MPAs. The graphene material has a reconfigurable surface conductivity that can be adjusted to function at the required value, thus allowing the required resonance frequency to be selected. The simulated tuneable antenna comprises a copper radiating patch with four graphene strips used for tuning purposes and is designed to cover a wide frequency band. The proposed antenna can be tuned directly by applying a direct current (DC) voltage to the graphene strips, resulting in a variation in the surface impedance of the graphene strips and leading to shifts in the resonance frequency.
Dual-band aperture coupled antenna with harmonic suppression capabilityTELKOMNIKA JOURNAL
The paper presents an aperture-coupled dual-band linearly-polarized antenna with harmonic suppression capability, operating at frequency 2.45 GHz and 5.00 GHz. In purpose of improving the directivity of antenna at the operating frequency of 2.45 GHz and 5.00 GHz, a modified inverted π-shaped slot-etched patch on the lower layer of the stacked antenna is introduced alongside the 50 Ω feed line. The harmonic suppression capability is achieved by the introduction of U-slot and asymmetrical left-right-handed stub at the transmission feed line, suppressing unwanted harmonic signals from 6.00 GHz up to 10.00 GHz. The final design of the antenna has produced very good reflection coefficient of -18.87 dB at 2.45 GHz and -19.57 dB at 5.00 GHz with third and higher order harmonic suppression up to -4 dB.
A miniaturized printed UWB antenna with dual notching for X-b and and aeronau...TELKOMNIKA JOURNAL
A low cost miniaturized UWB microstrip antenna with dual notched band for X band and aeronautical radio navigation (ARN) is presented in this article. The antenna (19 16×"> 25 mm2) is composed of a half-circular ring as a radiation patch with an incomplete ground plane. The measured results indicate a fractional bandwidth of 112% for 16S11≤-"> 10 dB between 3 to 10.6 GHz. The dual notched band has been achieved by incorporating window shaped microstrip closed ring resonators at the rear surface of the designed structure. The first notch band is centered at 7.5 GHz (7 8.1 GHz) to reject interference with X-band downlink (7.25 to 7.74 GHz) and second band centered at 9.1 GHz (8.6 9.4 GHz) to reject interference with aeronautical radio navigation (ARN) (8.7 to 9.2 GHz). The simulated and measured return loss, radiation pattern, and gain shows good agreement which confirms the applicability of the designed antenna for the intended UWB applications.
Enabling full-duplex in multiple access technique for 5G wireless networks ov...TELKOMNIKA JOURNAL
Nowadays, unmanned aerial vehicle (UAV) relays’assisted Internet of Things (IoT) systems provide facility in order to overcome the large scale fading between source and sink. The full-duplex scheme enables wireless network to provide higher spectrum efficient technology. This paper analyses performance of two users which are served by new emerging non-orthogonal multiple access (NOMA) technique. Exact outage probability of such two users are derived and checked via Monte-Carlo simulation. These analytical results provide guideline to design UAV in real application. This paper provides a comprehensive study to examine impact of interference, fixed power allocation factors to system performance.
Design and Analysis of Ku/K-band Circular SIW Patch Antenna Using 3D EM-based...TELKOMNIKA JOURNAL
Substrate Integrated Waveguide (SIW) antennas are considered as main radiators for RF and microwave wireless systems due to their low profile, low cost and soft integration with the other devices. The gain of a SIW patch antenna may be enhanced using different techniques such as Artificial Neural Networks (ANN) by modifying the antenna’s geometry with high efficiency comparing to electromagnetic techniques that take more time. This paper describes a novel structure of a circular SIW patch antenna design using a tree-dimensional electromagnetic (3D-EM) simulation based on ANN model which is developed as an accurate tool for synthesizing the forward side and then analyzing the reverse side of the problem. In this work, ANN algorithms are used for training the samples to provide precise geometrical dimensions of the SIW patch antenna with high accuracy for the target requirements. The antenna is designed to operate in Ku and K frequency bands, resonate at 16.10 GHz and 19.81 GHz respectively and show good performance resulting in low return losses of less than -10dB to -29dB for the selective frequency bands.
Development of patch stack antenna for CP-SAR sensorjournalBEEI
In this paper, we obtain the basic configuration of the left-hand circular polarization (LHCP) array two patches stack triangular truncated microstrip antenna. This construction use the basic corporate feed microstrip-line with modified lossless T-junction power divider on radiating patch for circularly polarized-synthetic aperture radar (CP-SAR) sensor embedded on airspace with compact, small, and simple configuration. The design of Circular Polarization (CP) is realized by truncating the whole three tips and adjusting the parameters of antenna at the resonant frequency, f=5.2 GHz. The results of characteristic performance and S-parameter for the LHCP array two patches stack antenna at the resonant frequency show successively about 7.24 dBic of gain, 1.99 dB of axial ratio (Ar), and -11.43 dB of S-parameter. Moreover, the impedance bandwidth and the 3 dB-Ar bandwidth of this antenna are around 560 MHz (10.77%) and 50 MHz (0.96%), respectively.
Analysis of near field distribution variation using awas electromagnetic code...csandit
Rapid Fluctuations and variations of signal strength at higher frequency range in Near Field
zone, is a common difficulty to achieve higher data rate. As signal varies continuously, it starts
decaying by the interference of the atmospheric obstructions and the electric field intensity
gradually decreases with the distance. This effect is observed by AWAS Electromagnetic Code
which predicts the rapid variations in electric field intensity irrespective of environment,
whereas statistical models do not capture the fundamental physics and variations as per
Environment. An Adequate and optimum values of these external parameters is essential for
controlled and efficient transmission.
A ring monopole quad band antenna loaded with metamaterial and slots for wire...journalBEEI
The present wireless applications demand a compact, multi-operated, and stable radiation pattern antenna with good gain and impedance matching performance. To accomplish this requirement. In this paper, we propose a compact metamaterial structure loaded quad band antenna. The structural specifications/layout of the antenna consists of a circular ring monopole fed by a microstrip line. The ground part of the antenna is loaded with a metamaterial rectangular split-ring resonator (RSRR), an L-shaped slot, and two horizontally placed rectangular slots parallel to each other. No external matching circuit is utilized and impedance matching is solely controlled by the placement of slots. The antenna shows operation at 2.1 GHz (2.01-2.24 GHz, a bandwidth of 230 MHz (WLAN)), 4.5 GHz (4.35-4.66 GHz, a bandwidth of 310 MHz (C-band)), 5.5 GHz (5.37-5.77 GHz bandwidth of 400 MHz (WiMAX)), and 7.2 GHz (7.08-7.33 GHz, a bandwidth of 250 MHz (satellite band)). The antenna exhibits good gain and stable radiation pattern in both the plane and thus can be utilized for aforementioned applications.
A novel multi-resonant and wideband fractal antenna for telecommunication ap...IJECEIAES
This letter presents the design, simulation, and measurement of a novel multiband fractal circular antenna for wireless applications. In the antenna design, we used a circular antenna where we took a ring. Then, in the first iteration, we added a new ring divided into two of the same size. For the second iteration, we added a ring of the same size after dividing it into two halves. In the third iteration, we added the third ring of the same size after dividing it into four. Due to the resonator defection, we were able to reduce the size of the starting antenna from 60×70×2 mm3 to 50×50×1.6 mm3 , to get the frequency of 2.48 GHz, and we generated new bandwidths with a high gain that reaches 5.02 dB. The proposed antenna radiation characteristics, such as the impedance matching, the gain, the radiation pattern, and the surface current distribution are presented and discussed. We find that the simulated and measured results are in acceptable agreement and affirm the good performance of the proposed antenna. The results obtained affirm that the proposed fractal antenna is a better candidate for integration into wireless communication circuits.
Gain enhancement of microstrip patch antenna using artificial magnetic conductorjournalBEEI
The paper presents an artificial magnetic conductor (AMC) structure to enhance the gain of the double microstrip patch antenna. By placing this kind of metamaterial in between the two Rogers RT5880 substrates, the antenna achieved lots of improvement especially in terms of size miniaturization, bandwidth, return loss, gain and efficiency. The antenna is intended to operate at 16 GHz where the prospect fifth generation (5G) spectrum might be located. Integration of AMC structure into the proposed antenna helps to improve nearly 16.3% of gain and almost 23.6% of size reduction.
Designing large-scale antenna array using sub-arrayjournalBEEI
Antenna array of large scale have been examined for different applications including 5G technology. To get better data rate or a reliable link substantial number of antenna arrays have been utilized to provide high multiplexing gains as well as array gains with high directivity. In this paper a simple but efficient implementation technique of using sub-arrays for the improvement of large-sized uniform arrays. By repeating a small sub-array multiple times large arrays can be designed. This implication of utilizing small array simplifies the design of a larger array which allows the designer to concentrate on the smaller sub-array before assembling larger arrays. So, by investigating the sub arrays the performance and radiation characteristics of large arrays can be anticipated. The array-factor for a planar sub-array of 2x2 (4 elements) is analyzed using Mat-lab software and then a large array is formed by placing the 2x2 sub-array indifferent configurations in a rectangular arrangements up to 8x8 planar array. And then the results are validated with CST (Computer simulation technology) simulation results.In this way the array-factors, directivities, HPBWs, and side lobes of the constructed large arrays are analyzed and associated with the small sub-array.
Simulation and optimization of tuneable microstrip patch antenna for fifth-ge...IJECEIAES
Microstrip patch antennas (MPAs) are known largely for their versatility in terms of feasible geometries, making them applicable in many distinct circumstances. In this paper, a graphene-based tuneable single/array rectangular microstrip patch antenna (MPA) utilizing an inset feed technique designed to function in multiple frequency bands are used in a fifth-generation (5G) wireless communications system. The tuneable antenna is used to eliminate the difficulties caused by the narrow bandwidths typically associated with MPAs. The graphene material has a reconfigurable surface conductivity that can be adjusted to function at the required value, thus allowing the required resonance frequency to be selected. The simulated tuneable antenna comprises a copper radiating patch with four graphene strips used for tuning purposes and is designed to cover a wide frequency band. The proposed antenna can be tuned directly by applying a direct current (DC) voltage to the graphene strips, resulting in a variation in the surface impedance of the graphene strips and leading to shifts in the resonance frequency.
Dual-band aperture coupled antenna with harmonic suppression capabilityTELKOMNIKA JOURNAL
The paper presents an aperture-coupled dual-band linearly-polarized antenna with harmonic suppression capability, operating at frequency 2.45 GHz and 5.00 GHz. In purpose of improving the directivity of antenna at the operating frequency of 2.45 GHz and 5.00 GHz, a modified inverted π-shaped slot-etched patch on the lower layer of the stacked antenna is introduced alongside the 50 Ω feed line. The harmonic suppression capability is achieved by the introduction of U-slot and asymmetrical left-right-handed stub at the transmission feed line, suppressing unwanted harmonic signals from 6.00 GHz up to 10.00 GHz. The final design of the antenna has produced very good reflection coefficient of -18.87 dB at 2.45 GHz and -19.57 dB at 5.00 GHz with third and higher order harmonic suppression up to -4 dB.
A miniaturized printed UWB antenna with dual notching for X-b and and aeronau...TELKOMNIKA JOURNAL
A low cost miniaturized UWB microstrip antenna with dual notched band for X band and aeronautical radio navigation (ARN) is presented in this article. The antenna (19 16×"> 25 mm2) is composed of a half-circular ring as a radiation patch with an incomplete ground plane. The measured results indicate a fractional bandwidth of 112% for 16S11≤-"> 10 dB between 3 to 10.6 GHz. The dual notched band has been achieved by incorporating window shaped microstrip closed ring resonators at the rear surface of the designed structure. The first notch band is centered at 7.5 GHz (7 8.1 GHz) to reject interference with X-band downlink (7.25 to 7.74 GHz) and second band centered at 9.1 GHz (8.6 9.4 GHz) to reject interference with aeronautical radio navigation (ARN) (8.7 to 9.2 GHz). The simulated and measured return loss, radiation pattern, and gain shows good agreement which confirms the applicability of the designed antenna for the intended UWB applications.
Enabling full-duplex in multiple access technique for 5G wireless networks ov...TELKOMNIKA JOURNAL
Nowadays, unmanned aerial vehicle (UAV) relays’assisted Internet of Things (IoT) systems provide facility in order to overcome the large scale fading between source and sink. The full-duplex scheme enables wireless network to provide higher spectrum efficient technology. This paper analyses performance of two users which are served by new emerging non-orthogonal multiple access (NOMA) technique. Exact outage probability of such two users are derived and checked via Monte-Carlo simulation. These analytical results provide guideline to design UAV in real application. This paper provides a comprehensive study to examine impact of interference, fixed power allocation factors to system performance.
Design and Analysis of Ku/K-band Circular SIW Patch Antenna Using 3D EM-based...TELKOMNIKA JOURNAL
Substrate Integrated Waveguide (SIW) antennas are considered as main radiators for RF and microwave wireless systems due to their low profile, low cost and soft integration with the other devices. The gain of a SIW patch antenna may be enhanced using different techniques such as Artificial Neural Networks (ANN) by modifying the antenna’s geometry with high efficiency comparing to electromagnetic techniques that take more time. This paper describes a novel structure of a circular SIW patch antenna design using a tree-dimensional electromagnetic (3D-EM) simulation based on ANN model which is developed as an accurate tool for synthesizing the forward side and then analyzing the reverse side of the problem. In this work, ANN algorithms are used for training the samples to provide precise geometrical dimensions of the SIW patch antenna with high accuracy for the target requirements. The antenna is designed to operate in Ku and K frequency bands, resonate at 16.10 GHz and 19.81 GHz respectively and show good performance resulting in low return losses of less than -10dB to -29dB for the selective frequency bands.
Development of patch stack antenna for CP-SAR sensorjournalBEEI
In this paper, we obtain the basic configuration of the left-hand circular polarization (LHCP) array two patches stack triangular truncated microstrip antenna. This construction use the basic corporate feed microstrip-line with modified lossless T-junction power divider on radiating patch for circularly polarized-synthetic aperture radar (CP-SAR) sensor embedded on airspace with compact, small, and simple configuration. The design of Circular Polarization (CP) is realized by truncating the whole three tips and adjusting the parameters of antenna at the resonant frequency, f=5.2 GHz. The results of characteristic performance and S-parameter for the LHCP array two patches stack antenna at the resonant frequency show successively about 7.24 dBic of gain, 1.99 dB of axial ratio (Ar), and -11.43 dB of S-parameter. Moreover, the impedance bandwidth and the 3 dB-Ar bandwidth of this antenna are around 560 MHz (10.77%) and 50 MHz (0.96%), respectively.
Analysis of near field distribution variation using awas electromagnetic code...csandit
Rapid Fluctuations and variations of signal strength at higher frequency range in Near Field
zone, is a common difficulty to achieve higher data rate. As signal varies continuously, it starts
decaying by the interference of the atmospheric obstructions and the electric field intensity
gradually decreases with the distance. This effect is observed by AWAS Electromagnetic Code
which predicts the rapid variations in electric field intensity irrespective of environment,
whereas statistical models do not capture the fundamental physics and variations as per
Environment. An Adequate and optimum values of these external parameters is essential for
controlled and efficient transmission.
A ring monopole quad band antenna loaded with metamaterial and slots for wire...journalBEEI
The present wireless applications demand a compact, multi-operated, and stable radiation pattern antenna with good gain and impedance matching performance. To accomplish this requirement. In this paper, we propose a compact metamaterial structure loaded quad band antenna. The structural specifications/layout of the antenna consists of a circular ring monopole fed by a microstrip line. The ground part of the antenna is loaded with a metamaterial rectangular split-ring resonator (RSRR), an L-shaped slot, and two horizontally placed rectangular slots parallel to each other. No external matching circuit is utilized and impedance matching is solely controlled by the placement of slots. The antenna shows operation at 2.1 GHz (2.01-2.24 GHz, a bandwidth of 230 MHz (WLAN)), 4.5 GHz (4.35-4.66 GHz, a bandwidth of 310 MHz (C-band)), 5.5 GHz (5.37-5.77 GHz bandwidth of 400 MHz (WiMAX)), and 7.2 GHz (7.08-7.33 GHz, a bandwidth of 250 MHz (satellite band)). The antenna exhibits good gain and stable radiation pattern in both the plane and thus can be utilized for aforementioned applications.
A novel multi-resonant and wideband fractal antenna for telecommunication ap...IJECEIAES
This letter presents the design, simulation, and measurement of a novel multiband fractal circular antenna for wireless applications. In the antenna design, we used a circular antenna where we took a ring. Then, in the first iteration, we added a new ring divided into two of the same size. For the second iteration, we added a ring of the same size after dividing it into two halves. In the third iteration, we added the third ring of the same size after dividing it into four. Due to the resonator defection, we were able to reduce the size of the starting antenna from 60×70×2 mm3 to 50×50×1.6 mm3 , to get the frequency of 2.48 GHz, and we generated new bandwidths with a high gain that reaches 5.02 dB. The proposed antenna radiation characteristics, such as the impedance matching, the gain, the radiation pattern, and the surface current distribution are presented and discussed. We find that the simulated and measured results are in acceptable agreement and affirm the good performance of the proposed antenna. The results obtained affirm that the proposed fractal antenna is a better candidate for integration into wireless communication circuits.
Novel fractal antenna for UWB applications using the coplanar waveguide feed ...IJECEIAES
In this study an original Coplanar Waveguide (CPW) antenna has been achieved into simulation and manufacturing in order to be an important candidate for the Ultra-wideband applications. The area of the proposed structure is 34mm x 43mm operating in the frequency range 3.1 GHz – 10.6 GHz released as UWB by the Federal Communications Commission (FCC). To perform the design of the proposed CPW antenna two electromagnetic solvers has been adopted which are CST of Microwave Studio and ADS of Agilent. The radiating patch has been chosen circular with fractal geometry based on circular slots with different sizes. The dielectric substrate is an Epoxy FR4 with a Relative permittivity 4.4, a thickness 1.6 and a loss tangent 0.025. To valid the functionality of the antenna two parameters has been computed which are the coefficient of reflection and the radiation pattern and confirmed into measurement by using the Network Analyser and the anechoic chamber.
A dual-frequency microstrip patch antennas has been presented and used for 802.11WLAN
applications. The antennas had been designed, simulated and parametrically studied in CST Microwave
studio. By introducing u-slot, dual-band operation with its operating mode centered at frequency 2.4GHz,
3.65GHz and 5.2GHz had been obtained. The gain and directivity had been improved by adjusting the
parameters of the antennas. The gain of the proposed designs was 6.019dBi, 4.04dBi and 6.22dBi and
directivity was 6.02dBi, 4.05dBi and 6.22dBi at resonant frequencies 2.4GHz, 3.6GHz and 5.2GHz
respectively. The patch antennas had been proposed to be used in portable devices that require
miniaturized constituent parts.
Wide to multiband elliptical monopole reconfigurable antenna for multimode sy...TELKOMNIKA JOURNAL
Wideband-multiband reconfigurable elliptical monopole antenna is investigated in this paper.
By having conventional elliptical monopole antenna, wideband operating frequency is obtained.
With the combination of dual pairs of slotted arms and a band-pass filter on the ground plane of the elliptical
monopole, multiband is achieved. Dual-band operating frequencies at 1.6 GHz and 2.6 GHz while wideband
operates from 3.35 GHz to 9 GHz. Therefore, wide range of wireless communication systems is obtained
from the proposed antenna to support the multiband mode (i.e. GPS and LTE) and UWB systems. Frequency
reconfigurable is achieved by controlling the switches integrated on the antenna structure. Simulated results
of reflection coefficient, radiation patterns and gain performance are presented. The proposed antenna
design is suitable candidate for different wireless communication applications.
International Journal of Computational Engineering Research(IJCER) ijceronline
nternational Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
A low cost fractal CPW fed antenna for UWB applications with a circular radia...TELKOMNIKA JOURNAL
In this study a validated antenna into simulation and through measurement has been described and analyzed. The coplanar waveguide (CPW) technique has been chosen to feed the radiating patch while the two ground planes have been partially designed in the top side of the substrate. The fractal geometry, applied to the circular radiator, has been obtained by merging the circular and rectangular shapes. The fiberglass FR-4, with a single side of 35μm copper thickness, has been used to achieve the antenna material with a permittivity of 4.4, a thickness of 1.6 mm, a loss tangent of 0.025 and an overall dimension of 34x43 mm2. The proposed CPW fractal antenna has been configured to operate in the frequency range 3.1-10.6 GHz published by the federal communications commission (FCC) as an ultra-wide band (UWB). To calculate the return loss, the gain, the current density and the radiation pattern of the simulated antenna, two electromagnetic solvers have been involved which are the CST microwave studio and ADS. The series of measurement have been performed by using the network analyzer and the anechoic chamber in order to confirm the computed antenna.
A pair of wideband antenna serve as an impedance transformer for the
proposed antenna, which consists of a dipole with periodic capacitive
loading. Periodic capacitive loading is achieved at each sector by adding
interlaced coupling lines. In order to create a broad impedance bandwidth,
the periodic interlaced coupling lines split each arm of the dipole into five
portions. Currents are dispersed on the various sections at different
frequencies. The suggested antenna is an excellent choice for radar
applications since it has a high gain and a low amount of cross polarisation.
With the aid of innovative design methods including codirectional inclusion
of interdigital capacitance, this research study proposes an interdigital
capacitance for wideband (WB) applications interdigital capacitor (IDC).
The suggested IDC antenna, which works between 4.70 and 11 GHz, has
dimensions of 6.36x6.35x1.6 mm3. This page explores in-depth data on gain
over frequency, far field patterns, and surface current distribution on
antennas. The suggested antenna's feasibility is shown by simulation data
that demonstrates excellent equality on return loss.
PLANAR ACS FED DUAL BAND ANTENNA WITH DGS FOR WIRELESS APPLICATIONS jantjournal
A novel Asymmetric Coplanar Strip (ACS) fed antenna with Defected Ground Structure (DGS) suitable for dual application is presented. The Method of Moments (MoM) based mentor graphics IE3D electromagnetic solver has been used for this design. Dual band operation has been obtained by modifying the ground plane of the proposed design with spur-slots. It has been fabricated and tested with the overall size of 21x15x1.6 mm3. The measured results indicate that the proposed antenna yields <-10dB impedance bandwidth of 13.13% and 9.86% which meets the requirement of
3.5GHz and 5.5GHz Wireless Local Area Network (WLAN) and World Wide Interoperability Microwave Access (WiMAX) applications. The approximate lumped equivalent circuit extraction for the proposed DGS fed dual band antenna has been discussed in detail. Because of its stable radiation patterns with low cross polarization,miniature size, high average antenna gain of 2.5dBi and good electromagnetic characteristics, the proposed antenna is a promising candidate for dual mode wireless communication devices.
PLANAR ACS FED DUAL BAND ANTENNA WITH DGS FOR WIRELESS APPLICATIONS jantjournal
A novel Asymmetric Coplanar Strip (ACS) fed antenna with Defected Ground Structure (DGS) suitable for dual application is presented. The Method of Moments (MoM) based mentor graphics IE3D electromagnetic solver has been used for this design. Dual band operation has been obtained by modifying the ground plane of the proposed design with spur-slots. It has been fabricated and tested with the overall size of 21x15x1.6 mm3 . The measured results indicate that the proposed
antenna yields <-10dB impedance bandwidth of 13.13% and 9.86% which meets the requirement of 3.5GHz and 5.5GHz Wireless Local Area Network (WLAN) and World Wide Interoperability Microwave Access (WiMAX) applications. The approximate lumped equivalent circuit extraction for the proposed DGS fed dual band antenna has been discussed in detail. Because of its stable radiation patterns with low cross polarization,miniature size, high average antenna gain of 2.5dBi
and good electromagnetic characteristics, the proposed antenna is a promising candidate for dual mode wireless communication devices.
PLANAR ACS FED DUAL BAND ANTENNA WITH DGS FOR WIRELESS APPLICATIONS jantjournal
A novel Asymmetric Coplanar Strip (ACS) fed antenna with Defected Ground Structure (DGS) suitable for dual application is presented. The Method of Moments (MoM) based mentor graphics IE3D electromagnetic solver has been used for this design. Dual band operation has been obtained by modifying the ground plane of the proposed design with spur-slots. It has been fabricated and tested with the overall size of 21x15x1.6 mm3. The measured results indicate that the proposed
antenna yields <-10dB impedance bandwidth of 13.13% and 9.86% which meets the requirement of 3.5GHz and 5.5GHz Wireless Local Area Network (WLAN) and World Wide Interoperability Microwave Access (WiMAX) applications. The approximate lumped equivalent circuit extraction for
the proposed DGS fed dual band antenna has been discussed in detail. Because of its stable radiation patterns with low cross polarization,miniature size, high average antenna gain of 2.5dBi
and good electromagnetic characteristics, the proposed antenna is a promising candidate for dual mode wireless communication devices.
PLANAR ACS FED DUAL BAND ANTENNA WITH DGS FOR WIRELESS APPLICATIONS jantjournal
A novel Asymmetric Coplanar Strip (ACS) fed antenna with Defected Ground Structure (DGS) suitable for dual application is presented. The Method of Moments (MoM) based mentor graphics IE3D electromagnetic solver has been used for this design. Dual band operation has been obtained by modifying the ground plane of the proposed design with spur-slots. It has been fabricated and tested with the overall size of 21x15x1.6 mm3 The measured results indicate that the proposed antenna yields <-10dB impedance bandwidth of 13.13% and 9.86% which meets the requirement of 3.5GHz and 5.5GHz Wireless Local Area Network (WLAN) and World Wide Interoperability
Microwave Access (WiMAX) applications. The approximate lumped equivalent circuit extraction for the proposed DGS fed dual band antenna has been discussed in detail. Because of its stable radiation patterns with low cross polarization,miniature size, high average antenna gain of 2.5dBi and good electromagnetic characteristics, the proposed antenna is a promising candidate for dual mode wireless communication devices.
PLANAR ACS FED DUAL BAND ANTENNA WITH DGS FOR WIRELESS APPLICATIONSjantjournal
A novel Asymmetric Coplanar Strip (ACS) fed antenna with Defected Ground Structure (DGS) suitable for dual application is presented. The Method of Moments (MoM) based mentor graphics IE3D electromagnetic solver has been used for this design. Dual band operation has been obtained by modifying the ground plane of the proposed design with spur-slots. It has been fabricated and tested with the overall size of 21x15x1.6 mm3. The measured results indicate that the proposed antenna yields <-10dB impedance bandwidth of 13.13% and 9.86% which meets the requirement of 3.5GHz and 5.5GHz Wireless Local Area Network (WLAN) and World Wide Interoperability
Microwave Access (WiMAX) applications. The approximate lumped equivalent circuit extraction for the proposed DGS fed dual band antenna has been discussed in detail. Because of its stable radiation patterns with low cross polarization,miniature size, high average antenna gain of 2.5dBi and good electromagnetic characteristics, the proposed antenna is a promising candidate for dual mode wireless communication devices.
Similar to Circularly polarized antenna array based on hybrid couplers for 5G devices (20)
Square transposition: an approach to the transposition process in block cipherjournalBEEI
The transposition process is needed in cryptography to create a diffusion effect on data encryption standard (DES) and advanced encryption standard (AES) algorithms as standard information security algorithms by the National Institute of Standards and Technology. The problem with DES and AES algorithms is that their transposition index values form patterns and do not form random values. This condition will certainly make it easier for a cryptanalyst to look for a relationship between ciphertexts because some processes are predictable. This research designs a transposition algorithm called square transposition. Each process uses square 8 × 8 as a place to insert and retrieve 64-bits. The determination of the pairing of the input scheme and the retrieval scheme that have unequal flow is an important factor in producing a good transposition. The square transposition can generate random and non-pattern indices so that transposition can be done better than DES and AES.
Hyper-parameter optimization of convolutional neural network based on particl...journalBEEI
Deep neural networks have accomplished enormous progress in tackling many problems. More specifically, convolutional neural network (CNN) is a category of deep networks that have been a dominant technique in computer vision tasks. Despite that these deep neural networks are highly effective; the ideal structure is still an issue that needs a lot of investigation. Deep Convolutional Neural Network model is usually designed manually by trials and repeated tests which enormously constrain its application. Many hyper-parameters of the CNN can affect the model performance. These parameters are depth of the network, numbers of convolutional layers, and numbers of kernels with their sizes. Therefore, it may be a huge challenge to design an appropriate CNN model that uses optimized hyper-parameters and reduces the reliance on manual involvement and domain expertise. In this paper, a design architecture method for CNNs is proposed by utilization of particle swarm optimization (PSO) algorithm to learn the optimal CNN hyper-parameters values. In the experiment, we used Modified National Institute of Standards and Technology (MNIST) database of handwritten digit recognition. The experiments showed that our proposed approach can find an architecture that is competitive to the state-of-the-art models with a testing error of 0.87%.
Supervised machine learning based liver disease prediction approach with LASS...journalBEEI
In this contemporary era, the uses of machine learning techniques are increasing rapidly in the field of medical science for detecting various diseases such as liver disease (LD). Around the globe, a large number of people die because of this deadly disease. By diagnosing the disease in a primary stage, early treatment can be helpful to cure the patient. In this research paper, a method is proposed to diagnose the LD using supervised machine learning classification algorithms, namely logistic regression, decision tree, random forest, AdaBoost, KNN, linear discriminant analysis, gradient boosting and support vector machine (SVM). We also deployed a least absolute shrinkage and selection operator (LASSO) feature selection technique on our taken dataset to suggest the most highly correlated attributes of LD. The predictions with 10 fold cross-validation (CV) made by the algorithms are tested in terms of accuracy, sensitivity, precision and f1-score values to forecast the disease. It is observed that the decision tree algorithm has the best performance score where accuracy, precision, sensitivity and f1-score values are 94.295%, 92%, 99% and 96% respectively with the inclusion of LASSO. Furthermore, a comparison with recent studies is shown to prove the significance of the proposed system.
A secure and energy saving protocol for wireless sensor networksjournalBEEI
The research domain for wireless sensor networks (WSN) has been extensively conducted due to innovative technologies and research directions that have come up addressing the usability of WSN under various schemes. This domain permits dependable tracking of a diversity of environments for both military and civil applications. The key management mechanism is a primary protocol for keeping the privacy and confidentiality of the data transmitted among different sensor nodes in WSNs. Since node's size is small; they are intrinsically limited by inadequate resources such as battery life-time and memory capacity. The proposed secure and energy saving protocol (SESP) for wireless sensor networks) has a significant impact on the overall network life-time and energy dissipation. To encrypt sent messsages, the SESP uses the public-key cryptography’s concept. It depends on sensor nodes' identities (IDs) to prevent the messages repeated; making security goals- authentication, confidentiality, integrity, availability, and freshness to be achieved. Finally, simulation results show that the proposed approach produced better energy consumption and network life-time compared to LEACH protocol; sensors are dead after 900 rounds in the proposed SESP protocol. While, in the low-energy adaptive clustering hierarchy (LEACH) scheme, the sensors are dead after 750 rounds.
Plant leaf identification system using convolutional neural networkjournalBEEI
This paper proposes a leaf identification system using convolutional neural network (CNN). This proposed system can identify five types of local Malaysia leaf which were acacia, papaya, cherry, mango and rambutan. By using CNN from deep learning, the network is trained from the database that acquired from leaf images captured by mobile phone for image classification. ResNet-50 was the architecture has been used for neural networks image classification and training the network for leaf identification. The recognition of photographs leaves requested several numbers of steps, starting with image pre-processing, feature extraction, plant identification, matching and testing, and finally extracting the results achieved in MATLAB. Testing sets of the system consists of 3 types of images which were white background, and noise added and random background images. Finally, interfaces for the leaf identification system have developed as the end software product using MATLAB app designer. As a result, the accuracy achieved for each training sets on five leaf classes are recorded above 98%, thus recognition process was successfully implemented.
Customized moodle-based learning management system for socially disadvantaged...journalBEEI
This study aims to develop Moodle-based LMS with customized learning content and modified user interface to facilitate pedagogical processes during covid-19 pandemic and investigate how teachers of socially disadvantaged schools perceived usability and technology acceptance. Co-design process was conducted with two activities: 1) need assessment phase using an online survey and interview session with the teachers and 2) the development phase of the LMS. The system was evaluated by 30 teachers from socially disadvantaged schools for relevance to their distance learning activities. We employed computer software usability questionnaire (CSUQ) to measure perceived usability and the technology acceptance model (TAM) with insertion of 3 original variables (i.e., perceived usefulness, perceived ease of use, and intention to use) and 5 external variables (i.e., attitude toward the system, perceived interaction, self-efficacy, user interface design, and course design). The average CSUQ rating exceeded 5.0 of 7 point-scale, indicated that teachers agreed that the information quality, interaction quality, and user interface quality were clear and easy to understand. TAM results concluded that the LMS design was judged to be usable, interactive, and well-developed. Teachers reported an effective user interface that allows effective teaching operations and lead to the system adoption in immediate time.
Understanding the role of individual learner in adaptive and personalized e-l...journalBEEI
Dynamic learning environment has emerged as a powerful platform in a modern e-learning system. The learning situation that constantly changing has forced the learning platform to adapt and personalize its learning resources for students. Evidence suggested that adaptation and personalization of e-learning systems (APLS) can be achieved by utilizing learner modeling, domain modeling, and instructional modeling. In the literature of APLS, questions have been raised about the role of individual characteristics that are relevant for adaptation. With several options, a new problem has been raised where the attributes of students in APLS often overlap and are not related between studies. Therefore, this study proposed a list of learner model attributes in dynamic learning to support adaptation and personalization. The study was conducted by exploring concepts from the literature selected based on the best criteria. Then, we described the results of important concepts in student modeling and provided definitions and examples of data values that researchers have used. Besides, we also discussed the implementation of the selected learner model in providing adaptation in dynamic learning.
Prototype mobile contactless transaction system in traditional markets to sup...journalBEEI
One way to prevent and reduce the spread of the covid-19 pandemic is through physical distancing program. This research aims to develop a prototype contactless transaction system using digital payment mechanisms and QR code technology that will be applied in traditional markets. The method used in the development of electronic market systems is a prototype approach. The application of QR code and digital payments are used as a solution to minimize money exchange contacts that are common in traditional markets. The results showed that the system built was able to accelerate and facilitate the buying and selling transaction process in traditional market environment. Alpha testing shows that all functional systems are running well. Meanwhile, beta testing shows that the user can very well accept the system that was built. The results of the study also show acceptance of the usefulness of the system being built, as well as the optimism of its users to be able to take advantage of this system both technologically and functionally, so its can be a part of the digital transformation of the traditional market to the electronic market and has become one of the solutions in reducing the spread of the current covid-19 pandemic.
Wireless HART stack using multiprocessor technique with laxity algorithmjournalBEEI
The use of a real-time operating system is required for the demarcation of industrial wireless sensor network (IWSN) stacks (RTOS). In the industrial world, a vast number of sensors are utilised to gather various types of data. The data gathered by the sensors cannot be prioritised ahead of time. Because all of the information is equally essential. As a result, a protocol stack is employed to guarantee that data is acquired and processed fairly. In IWSN, the protocol stack is implemented using RTOS. The data collected from IWSN sensor nodes is processed using non-preemptive scheduling and the protocol stack, and then sent in parallel to the IWSN's central controller. The real-time operating system (RTOS) is a process that occurs between hardware and software. Packets must be sent at a certain time. It's possible that some packets may collide during transmission. We're going to undertake this project to get around this collision. As a prototype, this project is divided into two parts. The first uses RTOS and the LPC2148 as a master node, while the second serves as a standard data collection node to which sensors are attached. Any controller may be used in the second part, depending on the situation. Wireless HART allows two nodes to communicate with each other.
Implementation of double-layer loaded on octagon microstrip yagi antennajournalBEEI
A double-layer loaded on the octagon microstrip yagi antenna (OMYA) at 5.8 GHz industrial, scientific and medical (ISM) Band is investigated in this paper. The double-layer consist of two double positive (DPS) substrates. The OMYA is overlaid with a double-layer configuration were simulated, fabricated and measured. A good agreement was observed between the computed and measured results of the gain for this antenna. According to comparison results, it shows that 2.5 dB improvement of the OMYA gain can be obtained by applying the double-layer on the top of the OMYA. Meanwhile, the bandwidth of the measured OMYA with the double-layer is 14.6%. It indicates that the double-layer can be used to increase the OMYA performance in term of gain and bandwidth.
The calculation of the field of an antenna located near the human headjournalBEEI
In this work, a numerical calculation was carried out in one of the universal programs for automatic electro-dynamic design. The calculation is aimed at obtaining numerical values for specific absorbed power (SAR). It is the SAR value that can be used to determine the effect of the antenna of a wireless device on biological objects; the dipole parameters will be selected for GSM1800. Investigation of the influence of distance to a cell phone on radiation shows that absorbed in the head of a person the effect of electromagnetic radiation on the brain decreases by three times this is a very important result the SAR value has decreased by almost three times it is acceptable results.
Exact secure outage probability performance of uplinkdownlink multiple access...journalBEEI
In this paper, we study uplink-downlink non-orthogonal multiple access (NOMA) systems by considering the secure performance at the physical layer. In the considered system model, the base station acts a relay to allow two users at the left side communicate with two users at the right side. By considering imperfect channel state information (CSI), the secure performance need be studied since an eavesdropper wants to overhear signals processed at the downlink. To provide secure performance metric, we derive exact expressions of secrecy outage probability (SOP) and and evaluating the impacts of main parameters on SOP metric. The important finding is that we can achieve the higher secrecy performance at high signal to noise ratio (SNR). Moreover, the numerical results demonstrate that the SOP tends to a constant at high SNR. Finally, our results show that the power allocation factors, target rates are main factors affecting to the secrecy performance of considered uplink-downlink NOMA systems.
Design of a dual-band antenna for energy harvesting applicationjournalBEEI
This report presents an investigation on how to improve the current dual-band antenna to enhance the better result of the antenna parameters for energy harvesting application. Besides that, to develop a new design and validate the antenna frequencies that will operate at 2.4 GHz and 5.4 GHz. At 5.4 GHz, more data can be transmitted compare to 2.4 GHz. However, 2.4 GHz has long distance of radiation, so it can be used when far away from the antenna module compare to 5 GHz that has short distance in radiation. The development of this project includes the scope of designing and testing of antenna using computer simulation technology (CST) 2018 software and vector network analyzer (VNA) equipment. In the process of designing, fundamental parameters of antenna are being measured and validated, in purpose to identify the better antenna performance.
Transforming data-centric eXtensible markup language into relational database...journalBEEI
eXtensible markup language (XML) appeared internationally as the format for data representation over the web. Yet, most organizations are still utilising relational databases as their database solutions. As such, it is crucial to provide seamless integration via effective transformation between these database infrastructures. In this paper, we propose XML-REG to bridge these two technologies based on node-based and path-based approaches. The node-based approach is good to annotate each positional node uniquely, while the path-based approach provides summarised path information to join the nodes. On top of that, a new range labelling is also proposed to annotate nodes uniquely by ensuring the structural relationships are maintained between nodes. If a new node is to be added to the document, re-labelling is not required as the new label will be assigned to the node via the new proposed labelling scheme. Experimental evaluations indicated that the performance of XML-REG exceeded XMap, XRecursive, XAncestor and Mini-XML concerning storing time, query retrieval time and scalability. This research produces a core framework for XML to relational databases (RDB) mapping, which could be adopted in various industries.
Key performance requirement of future next wireless networks (6G)journalBEEI
Given the massive potentials of 5G communication networks and their foreseeable evolution, what should there be in 6G that is not in 5G or its long-term evolution? 6G communication networks are estimated to integrate the terrestrial, aerial, and maritime communications into a forceful network which would be faster, more reliable, and can support a massive number of devices with ultra-low latency requirements. This article presents a complete overview of potential 6G communication networks. The major contribution of this study is to present a broad overview of key performance indicators (KPIs) of 6G networks that cover the latest manufacturing progress in the environment of the principal areas of research application, and challenges.
Noise resistance territorial intensity-based optical flow using inverse confi...journalBEEI
This paper presents the use of the inverse confidential technique on bilateral function with the territorial intensity-based optical flow to prove the effectiveness in noise resistance environment. In general, the image’s motion vector is coded by the technique called optical flow where the sequences of the image are used to determine the motion vector. But, the accuracy rate of the motion vector is reduced when the source of image sequences is interfered by noises. This work proved that the inverse confidential technique on bilateral function can increase the percentage of accuracy in the motion vector determination by the territorial intensity-based optical flow under the noisy environment. We performed the testing with several kinds of non-Gaussian noises at several patterns of standard image sequences by analyzing the result of the motion vector in a form of the error vector magnitude (EVM) and compared it with several noise resistance techniques in territorial intensity-based optical flow method.
Modeling climate phenomenon with software grids analysis and display system i...journalBEEI
This study aims to model climate change based on rainfall, air temperature, pressure, humidity and wind with grADS software and create a global warming module. This research uses 3D model, define, design, and develop. The results of the modeling of the five climate elements consist of the annual average temperature in Indonesia in 2009-2015 which is between 29oC to 30.1oC, the horizontal distribution of the annual average pressure in Indonesia in 2009-2018 is between 800 mBar to 1000 mBar, the horizontal distribution the average annual humidity in Indonesia in 2009 and 2011 ranged between 27-57, in 2012-2015, 2017 and 2018 it ranged between 30-60, during the East Monsoon, the wind circulation moved from northern Indonesia to the southern region Indonesia. During the west monsoon, the wind circulation moves from the southern part of Indonesia to the northern part of Indonesia. The global warming module for SMA/MA produced is feasible to use, this is in accordance with the value given by the validate of 69 which is in the appropriate category and the response of teachers and students through a 91% questionnaire.
An approach of re-organizing input dataset to enhance the quality of emotion ...journalBEEI
The purpose of this paper is to propose an approach of re-organizing input data to recognize emotion based on short signal segments and increase the quality of emotional recognition using physiological signals. MIT's long physiological signal set was divided into two new datasets, with shorter and overlapped segments. Three different classification methods (support vector machine, random forest, and multilayer perceptron) were implemented to identify eight emotional states based on statistical features of each segment in these two datasets. By re-organizing the input dataset, the quality of recognition results was enhanced. The random forest shows the best classification result among three implemented classification methods, with an accuracy of 97.72% for eight emotional states, on the overlapped dataset. This approach shows that, by re-organizing the input dataset, the high accuracy of recognition results can be achieved without the use of EEG and ECG signals.
Parking detection system using background subtraction and HSV color segmentationjournalBEEI
Manual system vehicle parking makes finding vacant parking lots difficult, so it has to check directly to the vacant space. If many people do parking, then the time needed for it is very much or requires many people to handle it. This research develops a real-time parking system to detect parking. The system is designed using the HSV color segmentation method in determining the background image. In addition, the detection process uses the background subtraction method. Applying these two methods requires image preprocessing using several methods such as grayscaling, blurring (low-pass filter). In addition, it is followed by a thresholding and filtering process to get the best image in the detection process. In the process, there is a determination of the ROI to determine the focus area of the object identified as empty parking. The parking detection process produces the best average accuracy of 95.76%. The minimum threshold value of 255 pixels is 0.4. This value is the best value from 33 test data in several criteria, such as the time of capture, composition and color of the vehicle, the shape of the shadow of the object’s environment, and the intensity of light. This parking detection system can be implemented in real-time to determine the position of an empty place.
Quality of service performances of video and voice transmission in universal ...journalBEEI
The universal mobile telecommunications system (UMTS) has distinct benefits in that it supports a wide range of quality of service (QoS) criteria that users require in order to fulfill their requirements. The transmission of video and audio in real-time applications places a high demand on the cellular network, therefore QoS is a major problem in these applications. The ability to provide QoS in the UMTS backbone network necessitates an active QoS mechanism in order to maintain the necessary level of convenience on UMTS networks. For UMTS networks, investigation models for end-to-end QoS, total transmitted and received data, packet loss, and throughput providing techniques are run and assessed and the simulation results are examined. According to the results, appropriate QoS adaption allows for specific voice and video transmission. Finally, by analyzing existing QoS parameters, the QoS performance of 4G/UMTS networks may be improved.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Cosmetic shop management system project report.pdfKamal Acharya
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The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Circularly polarized antenna array based on hybrid couplers for 5G devices
1. Bulletin of Electrical Engineering and Informatics
Vol. 10, No. 3, June 2021, pp. 1446~1454
ISSN: 2302-9285, DOI: 10.11591/eei.v10i3.3017 1446
Journal homepage: http://beei.org
Circularly polarized antenna array based on hybrid couplers
for 5G devices
Tan Minh Cao1
, Thao Hoang Thi Phuong2
, Thi Duyen Bui3
1
Department of Instrument and Industrial Informatics, Hanoi University of Science & Technology, Hanoi, Vietnam
2
Faculty of Electronics and Telecommunications, Electric Power University, Hanoi, Vietnam
3
Faculty of Control and Automation, Electric Power University, Hanoi, Vietnam
Article Info ABSTRACT
Article history:
Received Nov 13, 2020
Revised Mar 21, 2021
Accepted Apr 9, 2021
This paper depicts a wideband circularly polarized (CP) antenna for 5G
devices. The antenna array has a 3D structure including four simple printed
dipole elements with directional radiations, high gain, and high efficiency. It
achieves a CP by using the sequential rotation (SR) feeding based on 90°-
3dB hybrid couplers in the proposed feeding network. The antenna array
bandwidth is wide, 26.7%, with an operating frequency band from 3.35 GHz
to 4.35 GHz. The antenna achieves a high peak gain of 10.73 dBi and high
efficiency of 93.75%. Besides, the antenna gain is stable over the operating
bandwidth (BW). At the centre operating frequency of 3.75 GHz, the angle
of circular polarization is 51°. The antenna is designed and fabricated on the
Rogers 4003 C substrate. The measured S11 is well matching with the
simulation results. With the above characteristics, the proposed antenna can
be a suitable candidate for 5G devices.
Keywords:
5G
Antenna array
Beam steering antenna
Butler matrix
Circularly polarized
Hybrid coupler
Printed dipole
This is an open access article under the CC BY-SA license.
Corresponding Author:
Thi Duyen Bui
Faculty of Control and Automation
Electric Power University
235 Hoang Quoc Viet Street, Hanoi, Vietnam
Email: duyenbt@epu.edu.vn
1. INTRODUCTION
Circularly polarized (CP) microstrip antennas have been used widely in many communication
systems, including 5G mobile communication, because of their advantages over linearly-polarized antennas
in reducing energy loss, multipath effect, and Faraday rotation effect [1]. Also, 5G operating in both
spectrums, including lower frequencies, frequency range (FR1) (4.1 GHz-7.125 GHz), and higher
frequencies, FR2 (24.25 GHz-52.6 GHz), have attracted much attention [1]. There have been several
researches about CP antennas working at FR1 using several structures such as single-feed [2]-[12] or
multiple-feeds [13]-[17]. Using single-feed structures to achieve a CP antenna is the simplest technique, but
it has a limitation of narrow bandwidth. Meanwhile, multiple-feeds structures such as antenna arrays can give
not only wide bandwidth but also high gain. These CP antenna arrays have obtained significant
achievements. Still, higher gain, wider bandwidth, simpler structure requirements for FR1 bands have been a
challenge in designing CP antenna arrays.
This paper proposes a CP antenna array that consists of four dipole elements. Rogers 4003 C
substrate is chosen to design the antenna because of low weight, low loss, and high hardness. The SR
technique is applied for feeding network design using 90o
phase-shifters and quasi-equal-amplitude to obtain
the wideband CP antenna. Two CP modes of the antenna are obtained by changing the feeding point PIN-
diodes element to avoid the loss and non-linear effect. The antenna achieves a CP with a degree of 51°, a
2. Bulletin of Electr Eng & Inf ISSN: 2302-9285
Circularly polarized antenna array based on hybrid couplers for 5G devices (Tan Minh Cao)
1447
high gain of 10.73 dBi, and a wide bandwidth of 26.7%. The rest of this paper is organized is being as.
Section 2 presents the design of the 5G CP antenna as well as its simulated and measured results. The
conclusion of the paper is in section 3.
2. 5G CIRCULARLY POLARIZED ANTENNA DESIGN
This section presents the design of the 5G CP antenna including the antenna element, the antenna
array, and the feeding network in subsection 2.1, 2.2, and 2.3 respectively. The latest describes the simulated
and measured results of the proposed antenna as well as the discussion and the comparison between the
archived results and the publications.
2.1. Printed dipole antenna element
The 5G printed dipole element with “J”-Balun is proposed in Figure 1(a) according to the theory in
[17]-[22] but high gain and directional pattern. Thanks to achieving high efficiency, the dipole antennas are
often chosen to design CP antennas. The antenna element is designed on Rogers 4003 C substrate with a
dielectric constant of 3.55 and a height of 0.813 mm. On the one side of the substrate, the antenna includes a
radiator with two arms and a ground for obtaining directional radiation and high antenna gain. On the other
side, a “J” Balun is integrated into the feeding to ensure electricity balancing for two arms. Figure 1(b)
illustrates the equivalent circuit of J-Balun for impedance studying. The radiator and Balun's detail
dimensions are calculated similarly to the steps in [8]. The perfect matching is achieved when Lb =Lab =/4.
The antenna is designed for the center frequency of 3.75 GHz. The parameters of the proposed antenna are
calculated, optimized by CST software, and shown in Table 1. The antenna element prototype is presented in
Figure 1(c).
(a) (b)
(c)
Figure 1. The printed dipole element with “J”-Balun propose, (a) The structure of printed dipole antenna,
(b) The equivalent of the “J” Balun, (c) Prototyped
Table 1. Parameters of the printed dipole with integrated "J" Balun
Parameters Values (mm) Parameters Values (mm) Parameters Values(mm)
L 15.5 Lb 12 Wsg 2.5
Lf 14.5 W 2.5 Wa 1.85
Lab 20-8 Wf 8 Xsub 40
La 12.92 g 0.9 Ysub 60
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Figure 2 shows the S11 simulation results of the dipole antenna. The Figure shows that the antenna
bandwidth is from 3.6 GHz to 4 GHz (at S11 < -10 dB), and the simulation reflection coefficient S11 is -45 dB
at 3.75 GHz. Figure 3(a) presents the 3D radiation pattern of the antenna element and Figure 3(b) plots E-
plane and H-plane of the radiation pattern. The printed dipole antenna achieves a peak gain of 6.478 dBi, an
angular width (-3dB) of 129.30°, and total radiation efficiency of 96.63%.
Figure 2. The simulated reflection coefficients of printed dipole antenna
(a) (b)
Figure 3. These figures are, (a) 3D radiation pattern of the proposed dipole element at 3.75 GHz,
(b) Radiation pattern of the proposed dipole element at 3.75 GHz in E-plane and H-plane
2.2. Dipole antenna array
CP antennas can be achieved by using single-feed or multiple-feeds structures as mentioned in
section 1. Several techniques have been reported in recent decades such as dual-feed, mutual coupling and
reactive loading, stacked, aperture coupled, and sequentially rotated [23]. The CP antenna arrays that use
sequentially rotated feed network generate wideband, high gain, and CP radiation from a linear polarization
[5], [14], [16], [24]-[25].
Figure 4(a) shows the structure of the CP antenna array with a total dimension of 80×80×40 mm3
.
The antenna array consists of four above antenna elements, and the proposed feeding network presented in
the next section (subsection 2.3). Two neighboring dipole elements are perpendicular, and all four elements
are perpendicular to the feeding network. This configuration has the advantage of low mutual coupling
between these elements in the antenna array. The antenna obtains a wideband CP by applying the SR feeding
technique thanks to the feeding network. The excited phases feeding ports 2, 3, 4, 5 correspondings to four
dipoles 2, 3, 4, 5 are arranged 0°, 90°, 180°, and 270° as shown in Table 2.
4. Bulletin of Electr Eng & Inf ISSN: 2302-9285
Circularly polarized antenna array based on hybrid couplers for 5G devices (Tan Minh Cao)
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Table 2. Excited phases of antenna elements
Dipole 1 (Port 2) Dipole 2 (Port 3) Dipole 3 (Port 4) Dipole 4 (Port 5)
00
900
1800
2700
2.3. Feeding network design
The feeding network is illustrated in Figure 4(b), and the desired phase difference between adjacent
feeding ports presented in Table 2. It utilizes two 90°-3dB hybrid couplers and a 100 quarter-wavelength
transmission lines to create 90° and 180° phase shifts, respectively, and 70.7 quarter-wavelength
transmission lines for feeding and matching impedance between the elements.
(a) (b)
Figure 4. These figures are, (a) Structure of the CP antenna array, (b) The proposed feeding network
The 90° -3 dB hybrid coupler (HC) in the proposed feeding network is used for spliting power and
changing phases [11]. The HC is designed form on a conventional microstrip hybrid with four ports, as
depicted in Figure 5. The operation principle of the HC in Figure 5 is depicted is being as. The input power at
port 1 is divided into two equal parts to port 3 and port 4 with a 90-degree phase change between two
outputs, and it is not transmitted to port 5. S parameter of the HC is presented in (1).
Figure 5. Structure of hybrid coupler
Figure 6 presents the S parameters and the phase changes between the two output ports of the HC in
Figure 5. Figure 6(a) shows that the power at port 1 is divided into port 3 and port 4 while it is not
transmitted to port 2 in operating bandwidth. It can be seen in Figure 6(b) that the phase difference tween
port 3 and port 4 is 90o
at the center frequency of 3.75 GHz. The 3dB BW of the HC at -10 dB is from 3 GHz
to 4.5 GHz. These two HCs are integrated into the feeding network.
The input power with 50-ohm impedance at port 1as shown in Figure 4(b) is splited to feed to four
elements of the array. The dipole element feed impedance must be matched with feeding lines. The length of
the microstrip line from the feeding point (port 1) to port 3 (dipole 2) longer than to port 2 (dipole 1) a
quarter-wavelength for obtaining a 90-degree phase delay tween port 2 and port 3. This is similar to the pair
of dipole 3 (port 4)/dipole 2 (port 3) and dipole 4 (port 5)/dipole 3 (port 4). The width of the quarter-wave
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lines is calculated to ensure impedance matching between 50 Ω inputs of the dipole elements and 100 Ω lines
(width of W1) as well as between the input of subminiature version A (SMA) connector and 100 Ω lines. The
impedance of the lines to match 50 Ω input dipoles and 100 Ω lines are 70.7 Ω with the width of W2. The
value of W1 and W2 are calculated, then optimized by central standard time (CST) and presented in Table 3.
(a) (b)
Figure 6. These figures are, (a) The phase change of the output ports, (b) The simulated S parameter
Table 3. Dimension parameters of the lines in the feeding network
Parameters Values(mm) Parameters Values(mm)
W1 0.423 W2 0.95
Figure 7 depicts the simulated S-parameters of the feeding network, including amplitude and phase
when exciting port 1. The Figure 7(a) that antenna bandwidth is about 1 GHz (3.27 GHz-4.36 GHz). The
arguments of S21, S31, S41, S51 are approximately -6 dB at 3.6 GHz-4.0 GHz band. It means that the power
entering port 1 is equally divided into the rest four ports with low loss. Therefore, the antenna array obtains
the CP at the band of 3.65 GHz-3.93 GHz. The minimum Axial ratio (AR) of the antenna is below 2.5 dB at
3.6 GHz-4.0 GHz. It can be enhanced when the amplitude of excitation at all antenna element ports are the
same. According to Figure 7(b), the phase delay between two inputs of dipole 2/dipole 1, dipole 3/dipole 2,
and dipole 4/dipole3 is approximately 900
. This phase-difference is maintained at the band of 3.6 GHz-3.93
GHz. It explains why the CP antenna array has the CP at this band.
(a) (b)
Figure 7. Simulation results of array feeding network (FN), (a) Amplitude delivery created by the FN,
6. Bulletin of Electr Eng & Inf ISSN: 2302-9285
Circularly polarized antenna array based on hybrid couplers for 5G devices (Tan Minh Cao)
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(b) Phase delivery created by the FN
2.4. Results and discussion
The CP antenna array is designed and fabricated on the Rogers 4003 C substrate with the feeding
network and four dipole elements as presented above. Figure 8 shows the CP antenna array prototype with a
total dimension of 80×80×40 mm3
. Figure 9 shows the antenna reflection coefficient. The antenna array
bandwidth is increased by 16 % compared to single dipole antenna bandwidth. The CP antenna array has CP
from 3.65 GHz to 3.93 GHz. The measured S11 reflection coefficient is well matching with the simulation
results.
Figure 8. CP antenna prototype
Figure 9. Simulated and measured S11
Figure 10 plots the simulated radiation pattern of our CP antenna and AR in H-plane and E-plane of
the CP antenna array at 3.75 GHz. The Figure shows the antenna has a wide CP angle of 51° at 3.75 GHz.
Figure 11 depicts the simulated AR and gain of the CP antenna array vias frequency. The array (AR) is less
than 3 dB in the band of 3.6 GHz - 3.9 GHz (7.5%). It means that the proposed CP antenna array has high CP
bandwidth of 250 MHz. This band’s peak gain is more than 10.66 dBi with a maximum value of 10.73 dBi at
3.75 GHz. The total radiation efficiency is up to 93.75%. At 3.75 GHz, the beam-width of circular
polarization is 51°. Table 4 summarizes the results of several circular polarization antennas [5], [6], [16], [17]
which have a wide bandwidth, a circular polarization, and a 3D structure. Our proposed design has a higher
gain at the microwave frequency ranges than in [5], [6], [16], [17]. The proposed design has wider bandwidth
and wider bandwidth of CP compared to [6], [16]. However, the total dimension of antennas in [16], is
smaller than our antenna dimension. The smallest bandwidth antenna in [6] (BW=100 MHz) has the smallest
size (0.32×0.32×0.12). It is depict that the more broadband antenna is, the bigger the antenna dimension is.
The very high gain, CP, wideband, and low-profile are advantages of our proposed antenna. This antenna is
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easy to be integrated into the 5G system.
(a) (b)
Figure 10. These figures are, (a) Radiation arrangement of CP antenna at 3.75 GHz in E-plane and H-plane,
(b) Simulated AR in H-plane, E-plane of the CP antenna array at 3.75 GHz
Figure 11. Simulated antenna array gain and axial ratio
Table 4. Comparison with related works
Ref Freq (GHz) Gain peak (dBi) BW (MHz) BW of CP (GHz) Antenna size (λ)*
[5] 2.5 8.24 1200
1.4÷2.0
2.1÷2.35
2.4÷2.6
1×1×0.39
[6] 1.56 ~ 4.8 100 1.52÷1.56 0.32×0.32 ×0.12
[16] 1.6 ~ 5.5 500 1.52÷1.65 0.53×0.53
[17] 5.8 9.8 2800
5.5÷6.2
6.35÷6.8
0.9×0.9×0.38
This work 3.75 10.73 1000 3.6÷4.93 1.0×1.0×0.5
3. CONCLUSION
The wideband CP antenna array with four printed dipole antenna elements is depicted in this paper.
Our antenna array obtains the CP by applying the SR feeding approach based on the HC feeding network.
The antenna bandwidth is 26.7% (at -10 dB), and the beam-width of circular polarization is 51°. The antenna
achieves a peak gain up to 10.73 dBi. The centre frequency of 3.75 GHz, the antenna can be applied for 5G
devices that prefer high gain and wideband CP antenna characteristics.
REFERENCES
[1] U. Singh, S. Biswas, K. Singh, B. K. Kanaujia, and C.-P. Li, ''Beamforming Design for In-Band Full-Duplex Multi-
Cell Multi-User MIMO LSA Cellular Networks,'' IEEE Access, vol. 8, pp. 222355-222370, 2020, doi:
10.1109/ACCESS.2020.3043264.
8. Bulletin of Electr Eng & Inf ISSN: 2302-9285
Circularly polarized antenna array based on hybrid couplers for 5G devices (Tan Minh Cao)
1453
[2] M. Ali, R. Dougal, G. Yang, and H.-S. Hwang, ''Wideband (5-6 GHz WLAN band) circularly polarized patch
antenna for wireless power sensors,'' vol. 2, pp. 34-37, 2003, doi: 10.1109/APS.2003.1219173.
[3] A. Khidre, K. F. Lee, F. Yang, and A. Eilherbeni, ''Wideband Circularly Polarized E-Shaped Patch Antenna for
Wireless Applications [Wireless Corner],'' IEEE Antennas and Propagation Magazine, vol. 52, no. 5, pp. 219-229,
Oct. 2010, doi: 10.1109/MAP.2010.5687547.
[4] C.-J. Wang, M.-H. Shih, and L.-T. Chen, ''A Wideband Open-Slot Antenna with Dual-Band Circular Polarization,''
IEEE Antennas and Wireless Propagation Letters, vol. 14, pp. 1306-1309, 2015, doi:
10.1109/LAWP.2015.2403572.
[5] W.-S. Lee, K.-S. Oh, and J.-W. Yu, ''A wideband circular polarized planar monopole antenna array with circular
polarized and band-notched characteristics,'' Progress in Electromagnetics Research, vol. 128, pp. 381-398, 2012,
doi: 10.2528/PIER12040307.
[6] X. Ye, M. He, P. Zhou, and H. Sun, ''A Compact Single-Feed Circularly Polarized Microstrip Antenna with
Symmetric and Wide-Beamwidth Radiation Pattern,'' International Journal of Antennas and Propagation, vol.
2013, pp. 1-7, 2013, doi: 10.1155/2013/106516.
[7] L. Zhang, Q. Luo, and S. Gao, ''Wideband multilayer dual circularly-polarised antenna for array application,''
Electronics Letters, vol. 51, no. 25, pp. 2087-2089, Dec. 2015, doi: 10.1049/el.2015.3343.
[8] P. S. Hall, J. S. Dahele, and J. R. James, ''Design principles of sequentially fed, wide bandwidth, circularly
polarised microstrip antennas,'' IEEE Proceedings H Microwaves, Antennas and Propagation, vol. 136, no. 5, p.
381, 1989, doi: 10.1049/ip-h-2.1989.0069.
[9] D. Inserra, W. Hu, and G. Wen, ''Design of a Microstrip Series Power Divider for Sequentially Rotated Nonuniform
Antenna Array,'' International Journal of Antennas and Propagation, vol. 2017, pp. 1-8, 2017, doi:
10.1155/2017/9482979.
[10] Nasimuddin, Z. N. Chen, and K. P. Esselle, ''Wideband circularly polarized microstrip antenna array using a new
single feed network,'' Microwave and Optical Technology Letters, vol. 50, no. 7, pp. 1784-1789, Jul. 2008, doi:
10.1002/mop.23481.
[11] J. Zhang, H. Yang, and D. Yang, ''Design of a New High-Gain Circularly Polarized Antenna for Inmarsat
Communications,'' IEEE Antennas and Wireless Propagation Letters, vol. 11, pp. 350-353, 2012, doi:
10.1109/LAWP.2012.2191382.
[12] S. X. Ta and I. Park, ''Compact Wideband Circularly Polarized Patch Antenna Array Using Metasurface,'' IEEE
Antennas and Wireless Propagation Letters, vol. 16, pp. 1932-1936, 2017, doi: 10.1109/LAWP.2017.2689161.
[13] T. Varum, J. N. Matos, P. Pinho, and R. Abreu, ''Non-uniform broadband circularly polarized antenna array for
vehicular communications,'' IEEE Transactions on Vehicular Technology, pp. 1-1, 2015, doi:
10.1109/TVT.2015.2500520.
[14] T. Tasuku and T. Nasato, ''Wideband circularly polarised array antenna with sequential rotationsand phase shifts of
elements,'' in ISAP, Tokyo, Japan, 1985, pp. 117-120.
[15] L. Baggen, S. Holzwarth, and W. Simon, ''Phase array using the sequential rotation printed: analysis of coupling
effects,'' Carl-Friedrich-Gauss-Str. 2, D-47475 Kamp-Lintfort, Germany, IMST GmbH.
[16] Y. Luo, Q.-X. Chu, and L. Zhu, ''A Low-Profile Wide-Beamwidth Circularly-Polarized Antenna via Two Pairs of
Parallel Dipoles in a Square Contour,'' IEEE Transactions on Antennas and Propagation, vol. 63, no. 3, pp. 931-
936, Mar. 2015, doi: 10.1109/TAP.2014.2387438.
[17] T. D. Bui, Q. C. Nguyen, and M. T. Le, ''Novel wideband circularly polarized antenna for wireless applications,'' in
Microwave Conference (APMC), 2017 IEEE Asia Pacific, Kuala Lumpur, Malaysia, Nov. 2017, pp. 430-433, doi:
10.1109/APMC.2017.8251472.
[18] C. Wang and Y. Ge, ''A Novel Broadband Printed Dipole Antenna and Its Application for TD-LTE
Communications,'' International Journal of Antennas and Propagation, vol. 2014, p. e960963, Sep. 2014, doi:
10.1155/2014/960963.
[19] H. Jingjian, Z. Xiaofa, X. Shaoyi, W. Weiwei, and Y. Naichang, ''Suppression of Cross-Polarization of the
Microstrip Integrated Balun-Fed Printed Dipole Antenna,'' International Journal of Antennas and Propagation, vol.
2014, p. e765891, Apr. 2014, doi: 10.1155/2014/765891.
[20] M. Hamid and R. Hamid, ''Equivalent circuit of dipole antenna of arbitrary length,'' IEEE Transactions on Antennas
and Propagation, vol. 45, no. 11, pp. 1695-1696, Nov. 1997, doi: 10.1109/8.650083.
[21] K. V. Puglia, ''Electromagnetic simulation of some common balun structures,'' IEEE Microwave Magazine, vol. 3,
no. 3, pp. 56-61, Sep. 2002, doi: 10.1109/MMW.2002.1028363.
[22] W. Roberts, ''A New Wide-Band Balun,'' Proceedings of the IRE, vol. 45, no. 12, pp. 1628-1631, 1957, doi:
10.1109/JRPROC.1957.278293.
[23] G. Kumar and K. P. Ray, ''Broadband microstrip antennas,'' Boston, Mass: Artech House, 2003.
[24] J. Huang, ''A technique for an array to generate circular polarization with linearly polarized elements,'' IEEE
Transactions on Antennas and Propagation, vol. 34, no. 9, pp. 1113-1124, Sep. 1986, doi:
10.1109/TAP.1986.1143953.
[25] N. H. Nguyen, et al., ''A Novel Wideband Circularly Polarized Antenna for RF Energy Harvesting in Wireless
Sensor Nodes,'' International Journal of Antennas and Propagation, vol. 2018, pp. 1-9, 2018, doi:
10.1155/2018/1692018.
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BIOGRAPHIES OF AUTHORS
Tan Minh Cao received his Dipl. of Engineer (2020). He is a key member of Radio Frequency
group (RF3i) at Department of Instrumentation and Industrial Informatics (3I), School of
Electrical Engineering (SEE), Hanoi university of Science and Technology (HUST). His current
interests include antenna design, high-frequency circuits, wireless communication, filter design,
MIMO antenna, array antenna synthesis. He has experience in research on 5G systems antenna
for base station and devices. Now he is working in Research & Development Department (R&D)
at ACE antenna Company in Vietnam. His work is to design the antenna and filter for array
antenna 4G. He is also researching and developing for 5G systems.
Thao Hoang Thi Phuong received the Dipl. of Engineer (2004), Master of Science (2007), and
PhD degree (2019) in Electronics and Telecommunications from Hanoi University of Science
and Technology, Vietnam. Currently, she is a lecturer at Electronics and Telecommunications
Faculty, Electric Power University, Vietnam. Her research interests are antenna design, high-
frequency circuits, metamaterials, wireless communication, and localization systems. She has
had serveral publicattions in the ISI, Scopus jounals and international conferences in antenna and
wireless communication field. She has a total experience of 15 years teaching and researching
experience.
Thi Duyen Bui graduated in the field of Instrumentation and Industrial Informatics in 2004 and
completed the master’s degree in Control Engineering and Automation in 2007 at Hanoi
University of Science and Technology. She is a PhD in Control and Automation Engineering,
majoring in Measurement at Hanoi University of Science and Technology in 2020. Since 2005,
Thi Duyen Bui is working as a lecturer at the Faculty of Automation Technology, Electric Power
University. Her main research areas are antennas and high-frequency circuits, wireless
communication, indoor localization system, metamaterials, and design of embedded systems for
control and automation systems.