An electrically steerable beam is an essential standard in the recent wireless application in order
to increase the gain and reduce the interference. However, high performance of amplitude besides low
phase error difficult to achieve without indicators are used to set lens parameters to desired optimum
performance design level. In this paper, the introduced microstrip lens has examined a comprehensive
explanation for parameters and indications amid a full wave structure methodology. Further, Phase and
energy coupling between excited ports and received ports besides phase error and its relation with
the lens parameters design are explained in detailed. A wideband beamforming network based on a
printed microstrip Rotman lens with a ±26o scanning angle was designed in this study. The designed lens
operates at 2.45 GHz with 592 MHz bandwidth. The lens consists of five switchable ports (input ports) with
four output ports that connected to the microstrip patch antennas. The five switchable ports were used to
realize the scanning beams angle in the azimuth plane. The proposed model is simulated by CST
Microwave Studio and fabricated on FR-4 with 1.565 mm thickness and 4.2 permittivity. A good agreement
between simulation and measurement results were achieved.
A new approach for impedance matching rotman lens using defected ground struc...journalBEEI
Many recent radar applications and smart antenna are based on the electronically steerable beam in order to increase the performance of targeting the desired scan angle with the high performance of gain and directivity. Scanning angle with ±26o based on Microstrip Rotman lens and design frequency 2.45 GHz is presented in this study. Five beam ports provide five output beams directed the beams in five different scanning angles in the azimuth plane is provided. The traditional matching method by tapering the transmission line in order to guarantee a smooth energy transition from the 50 Ω input ports is replaced by Defected Ground Structure to achieve an acceptable return loss with a linear progressive phase for each beam port. The new approach is providing increasing in the scan angle. Besides, the size miniaturization is achieved by removing the tapering length and reduces the total size of the lens length by 23.67 mm. The proposed model is implemented using Computer Simulation Technology (CST) using the FR-4 substrate and the measurements lead to a good validation.
Antenna is the most important part of wireless communication. The recent growth in this industry makes the antenna more advanced and reliable. In various fields we need the use of highly characteristics antennas and these characteristics are based upon some parameters like bandwidth, gain, directivity etc. As compared to other antennas microstrip antenna can make possible to achieve the required characteristics for efficient communication because they are easily to fabricate and reduces the cost also. To make the microstrip antenna more advanced it use defected ground structure (DGS). The DGS structures are introduce to improve the performance of planar array antenna in terms of return loss, gain, directivity and voltage standing wave ratio. The goal of this paper is to understand the mathematical terms of antenna and feeding techniques so that it possible to know how to make the Microstrip antenna with DGS as more highly characterized antenna.
Circular Patch Antenna Performance using EBG StructureIDES Editor
Electromagnetic Band-Gap (EBG) structures are a
popular and efficient technique for microwave applications.
EBG may be combined with microstrip antenna to increase
the diversity gain, the radiation efficiency and/or to suppress
surface waves, to reduce the side lobes of the radiation pattern
and to increase the bandwidth. In this paper, two different
structures will be presented and discussed, which involve: (1)
EBG structure fed by circular patch antenna, and (2) circular
patch antenna surrounded by one row of EBG structure. The
influence of the EBG structure on the radiation patterns is
investigated. The effect of the surface waves is also considered.
Finally, the reduction of the side lobes of the radiation pattern
to increase the bandwidth is presented.
Controlling the Radiation Pattern of Patch Antenna Using Switchable EBGTELKOMNIKA JOURNAL
The advantages of the beam steering technique are the reduction of interference, save power and to maximize connectivity for point to multi points. Antenna gain degradation is a big problem in the beam steering technique. A new antenna structure is formed by combining the concept of mushroom-like EBG structure with the switching diode to produce the radation pattern control. All sides of the patch antenna are surrounded by several cells for EBG structure. In both of the the left and right sides, through a switching pin diode, the ground plane is attached to vias. The band-stop and band-pass properties of the EBG sector can be changed with the help of switching the diode between ON and OFF state, thus yielding the beam steering into that particular sector. At 6 GHz operational frequency, this structure has the ability to steer 40º (from -20º to +20º) while minimal diodes are utilized, directivity of 10 dBi, gain 9.86 dB and the efficiency is 96.5%. This approach is robust to gain degradation and the main lobe gain is approximately constant for all steering angles.
Wide slit rectangular microstrip antenna with spiral ebg structureeSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and
2D-EBG resembles like conventional plane reflector. The simulated results are presented.
A new approach for impedance matching rotman lens using defected ground struc...journalBEEI
Many recent radar applications and smart antenna are based on the electronically steerable beam in order to increase the performance of targeting the desired scan angle with the high performance of gain and directivity. Scanning angle with ±26o based on Microstrip Rotman lens and design frequency 2.45 GHz is presented in this study. Five beam ports provide five output beams directed the beams in five different scanning angles in the azimuth plane is provided. The traditional matching method by tapering the transmission line in order to guarantee a smooth energy transition from the 50 Ω input ports is replaced by Defected Ground Structure to achieve an acceptable return loss with a linear progressive phase for each beam port. The new approach is providing increasing in the scan angle. Besides, the size miniaturization is achieved by removing the tapering length and reduces the total size of the lens length by 23.67 mm. The proposed model is implemented using Computer Simulation Technology (CST) using the FR-4 substrate and the measurements lead to a good validation.
Antenna is the most important part of wireless communication. The recent growth in this industry makes the antenna more advanced and reliable. In various fields we need the use of highly characteristics antennas and these characteristics are based upon some parameters like bandwidth, gain, directivity etc. As compared to other antennas microstrip antenna can make possible to achieve the required characteristics for efficient communication because they are easily to fabricate and reduces the cost also. To make the microstrip antenna more advanced it use defected ground structure (DGS). The DGS structures are introduce to improve the performance of planar array antenna in terms of return loss, gain, directivity and voltage standing wave ratio. The goal of this paper is to understand the mathematical terms of antenna and feeding techniques so that it possible to know how to make the Microstrip antenna with DGS as more highly characterized antenna.
Circular Patch Antenna Performance using EBG StructureIDES Editor
Electromagnetic Band-Gap (EBG) structures are a
popular and efficient technique for microwave applications.
EBG may be combined with microstrip antenna to increase
the diversity gain, the radiation efficiency and/or to suppress
surface waves, to reduce the side lobes of the radiation pattern
and to increase the bandwidth. In this paper, two different
structures will be presented and discussed, which involve: (1)
EBG structure fed by circular patch antenna, and (2) circular
patch antenna surrounded by one row of EBG structure. The
influence of the EBG structure on the radiation patterns is
investigated. The effect of the surface waves is also considered.
Finally, the reduction of the side lobes of the radiation pattern
to increase the bandwidth is presented.
Controlling the Radiation Pattern of Patch Antenna Using Switchable EBGTELKOMNIKA JOURNAL
The advantages of the beam steering technique are the reduction of interference, save power and to maximize connectivity for point to multi points. Antenna gain degradation is a big problem in the beam steering technique. A new antenna structure is formed by combining the concept of mushroom-like EBG structure with the switching diode to produce the radation pattern control. All sides of the patch antenna are surrounded by several cells for EBG structure. In both of the the left and right sides, through a switching pin diode, the ground plane is attached to vias. The band-stop and band-pass properties of the EBG sector can be changed with the help of switching the diode between ON and OFF state, thus yielding the beam steering into that particular sector. At 6 GHz operational frequency, this structure has the ability to steer 40º (from -20º to +20º) while minimal diodes are utilized, directivity of 10 dBi, gain 9.86 dB and the efficiency is 96.5%. This approach is robust to gain degradation and the main lobe gain is approximately constant for all steering angles.
Wide slit rectangular microstrip antenna with spiral ebg structureeSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
PERFORMANCE ANALYSIS OF 2D-EBG UNDER MONOPOLE ANTENNAjantjournal
The artificial properties in two dimensional electromagnetic structures (2D-EBGs), such as PMC and Band Reject Region are investigated for a proposed structure of square shaped mushroom. The radiation characteristics of monopole antenna over this 2D-EBG is tested by considering two cases. During first case monopole antenna is made to operate within band rejection region. Second case monopole antenna made operate outside the band rejection range. The obtained results during first case is showing enhancement in operating band width and smoother radiation pattern. In second case the effect is null and
2D-EBG resembles like conventional plane reflector. The simulated results are presented.
E shape microstrip patch antenna design for wimax applications, international...Sk Sohag
This paper presents the design & simulation of E-shape microstrip patch antenna exhibiting wideband operating frequencies for various wireless applications. This antenna will provide the wide bandwidth which is required in various applications like remote sensing, biomedical application, mobile radio satellite, wireless communication etc. The coaxial feed or probe feed technique is used in the experiment. The performance of the designed antenna was analyzed in terms of bandwidth, gain, return loss, VSWR, and radiation pattern. The design is optimized to meet the best possible result. The proposed antenna is designed by air substrate which has a dielectric constant of 1.0006. The results show the wideband antenna is able to operate from 8.80 to 13.49 GHz frequency band with optimum frequency at 8.73 GHz.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
Electromagnetic Bandgap Structure for Antenna Design iosrjce
A dual band electromagnetic band gap structure is designed, simulated and measured. This is
carried out using CST microwave studio software, the design is carried out on FR-4 substrate by Method of
Suspended Transmission Line. The structure posses a dual band gap that effectively suppress surface wave at
the dual frequencies. The result from the simulation gives dual band gaps that resonate at 1.8GHz and 4.0GHz
and the measured result resonate at 1.8GHz and 4.3GHz, this show there is a good agreement between the two
results. The structure is simple and easily incorporated with microwave and wireless devices
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.
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.
Circularly polarized antenna array based on hybrid couplers for 5G devicesjournalBEEI
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.
The Microstrip antenna has been commercially used in many applications, such as direct broadcast
satellite service, mobile satellite communications, global positioning system, medical hyperthermia usage,
etc. The patch antenna of the size reduction at a given operating frequency is obtained. Mobile personal
communication systems and wireless computer networks are most commonly used nowadays and they are
in need of antennas in different frequency bands. In regulate to without difficulty incorporate these
antennas into individual systems, a micro strip scrap transmitter have been preferred and intended for a
convinced divergence. There is also an analysis of radiation pattern, Gain of the antenna, Directivity of the
antenna, Electric Far Field. The simulations results are obtained by using electromagnetic simulation
software called feko software are presented and discussed.
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.
Radiation pattern control of microstrip antenna in elevation and azimuth plan...IJECEIAES
An important issue in wireless communication systems, which is related to the antenna gain degradation in case of changing the main direction of the antenna radiation pattern, this variation is not approval in many communications systems. In order to improve antenna radiation performances, Electromagnetic band gap (EBG) - antenna with radiation pattern control capability is presented. Mushroom-like EBG structure for suppressing surface waves has been combined, with the switching diode to produce the radiation pattern control with improving antenna characteristics of gain, directivity and efficiency. EBG of several cells are surrounded the patch antenna and placed symmetrically for the two opposite sides, generating different radiation patterns control ability in both the elevation (E) (-20° < φ < 20°) and azimuth (Z) planes (−18° < θ < 18°). At the ground plane of antenna the diodes have been switched ON and OFF states, the EBG sector properties in stop band (connecting vias) and pass band (disconnecting vias) are altered. Using CST Microwave Studio (CST MWS) the results show the flexibility in radiation pattern control for the Z and E planes using only four diodes. Antenna directivity of 10 dBi, gain 9.86 dB and efficiency 96.5% at the operating frequency of 6 GHz, more results for all direction has been stated in Table1. Significantly, unlike a conventional beam steering, this method does not suffering from gain degradation and the main lobe gain is approximately constant for all steerig angles.
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.
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Design and implementation of microstrip rotman lens for ISM band applicationsjournalBEEI
This work presents the design and implementation of Rotman lens as a beam steering device for Industrial, Scientific, and Medical (ISM) applications. 2.45 GHz is considered as a center frequency design with (2-6) GHz frequency bandwidth. The beam steering is examined to cover ±21o scan angle with maximum main lobe magnitude 10.1 dBi, rectangular patch antennas are used as radiation elements to beam the output far field. The work is extended to compare between the tapered line which is used for matching between 50-Ω ports and lens cavity. CST microwave simulation studio results show that the rectangular taper line can yield 2 dB return loss less than linear taper line with a little bit shifting in responses for same input and load impedance.
In this paper, a novel multi-frequency microstrip antenna with complementary ring slot resonator (CRSR) structure that satisfies Bluetooth, worldwide interoperability for microwave access (WiMAX), and wireless local area network (WLAN) applications is proposed. The conventional antenna consists of a circular microstrip patch at a resonance frequency band of 2.5 GHz. By loading two CRSR at the radiating element, three operating frequency bands 2.5 GHz, 3.6 GHz, and 5.2 GHz are achieved. The operational bands covered by the antenna are Bluetooth 2.5 GHz, WiMAX 3.6 GHz, and WLAN 5.2 GHz. The insertion of CRSR to patch antenna has made it possible to compact and simple design, and miniaturized antenna for cognitive radio. Moreover, the directivity of the proposed antenna is adequate with acceptable radiation properties and perfectly matches with the simulated and measured results.
E shape microstrip patch antenna design for wimax applications, international...Sk Sohag
This paper presents the design & simulation of E-shape microstrip patch antenna exhibiting wideband operating frequencies for various wireless applications. This antenna will provide the wide bandwidth which is required in various applications like remote sensing, biomedical application, mobile radio satellite, wireless communication etc. The coaxial feed or probe feed technique is used in the experiment. The performance of the designed antenna was analyzed in terms of bandwidth, gain, return loss, VSWR, and radiation pattern. The design is optimized to meet the best possible result. The proposed antenna is designed by air substrate which has a dielectric constant of 1.0006. The results show the wideband antenna is able to operate from 8.80 to 13.49 GHz frequency band with optimum frequency at 8.73 GHz.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
Electromagnetic Bandgap Structure for Antenna Design iosrjce
A dual band electromagnetic band gap structure is designed, simulated and measured. This is
carried out using CST microwave studio software, the design is carried out on FR-4 substrate by Method of
Suspended Transmission Line. The structure posses a dual band gap that effectively suppress surface wave at
the dual frequencies. The result from the simulation gives dual band gaps that resonate at 1.8GHz and 4.0GHz
and the measured result resonate at 1.8GHz and 4.3GHz, this show there is a good agreement between the two
results. The structure is simple and easily incorporated with microwave and wireless devices
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.
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.
Circularly polarized antenna array based on hybrid couplers for 5G devicesjournalBEEI
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.
The Microstrip antenna has been commercially used in many applications, such as direct broadcast
satellite service, mobile satellite communications, global positioning system, medical hyperthermia usage,
etc. The patch antenna of the size reduction at a given operating frequency is obtained. Mobile personal
communication systems and wireless computer networks are most commonly used nowadays and they are
in need of antennas in different frequency bands. In regulate to without difficulty incorporate these
antennas into individual systems, a micro strip scrap transmitter have been preferred and intended for a
convinced divergence. There is also an analysis of radiation pattern, Gain of the antenna, Directivity of the
antenna, Electric Far Field. The simulations results are obtained by using electromagnetic simulation
software called feko software are presented and discussed.
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.
Radiation pattern control of microstrip antenna in elevation and azimuth plan...IJECEIAES
An important issue in wireless communication systems, which is related to the antenna gain degradation in case of changing the main direction of the antenna radiation pattern, this variation is not approval in many communications systems. In order to improve antenna radiation performances, Electromagnetic band gap (EBG) - antenna with radiation pattern control capability is presented. Mushroom-like EBG structure for suppressing surface waves has been combined, with the switching diode to produce the radiation pattern control with improving antenna characteristics of gain, directivity and efficiency. EBG of several cells are surrounded the patch antenna and placed symmetrically for the two opposite sides, generating different radiation patterns control ability in both the elevation (E) (-20° < φ < 20°) and azimuth (Z) planes (−18° < θ < 18°). At the ground plane of antenna the diodes have been switched ON and OFF states, the EBG sector properties in stop band (connecting vias) and pass band (disconnecting vias) are altered. Using CST Microwave Studio (CST MWS) the results show the flexibility in radiation pattern control for the Z and E planes using only four diodes. Antenna directivity of 10 dBi, gain 9.86 dB and efficiency 96.5% at the operating frequency of 6 GHz, more results for all direction has been stated in Table1. Significantly, unlike a conventional beam steering, this method does not suffering from gain degradation and the main lobe gain is approximately constant for all steerig angles.
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.
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Design and implementation of microstrip rotman lens for ISM band applicationsjournalBEEI
This work presents the design and implementation of Rotman lens as a beam steering device for Industrial, Scientific, and Medical (ISM) applications. 2.45 GHz is considered as a center frequency design with (2-6) GHz frequency bandwidth. The beam steering is examined to cover ±21o scan angle with maximum main lobe magnitude 10.1 dBi, rectangular patch antennas are used as radiation elements to beam the output far field. The work is extended to compare between the tapered line which is used for matching between 50-Ω ports and lens cavity. CST microwave simulation studio results show that the rectangular taper line can yield 2 dB return loss less than linear taper line with a little bit shifting in responses for same input and load impedance.
In this paper, a novel multi-frequency microstrip antenna with complementary ring slot resonator (CRSR) structure that satisfies Bluetooth, worldwide interoperability for microwave access (WiMAX), and wireless local area network (WLAN) applications is proposed. The conventional antenna consists of a circular microstrip patch at a resonance frequency band of 2.5 GHz. By loading two CRSR at the radiating element, three operating frequency bands 2.5 GHz, 3.6 GHz, and 5.2 GHz are achieved. The operational bands covered by the antenna are Bluetooth 2.5 GHz, WiMAX 3.6 GHz, and WLAN 5.2 GHz. The insertion of CRSR to patch antenna has made it possible to compact and simple design, and miniaturized antenna for cognitive radio. Moreover, the directivity of the proposed antenna is adequate with acceptable radiation properties and perfectly matches with the simulated and measured results.
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.
Modelling Optical Waveguide Bends by the Method of LinesTELKOMNIKA JOURNAL
A rigorous analytical and semi analytical method of lines has been used to calculate the
transverse-electric field attenuation coefficient of guided mode as it travels in waveguide bends structure.
Both approaches then were compared to get a better understanding on how the attenuation behaves along
single curve waveguides with constant radius of curvature. The Helmholtz Equation in polar coordinate
was transformed into a curvalinier coordinate to simulate the waveguide bends using the method of line
analysis. The simple absorption boundary conditions are used into the method of lines to demonstrate
evanescent field of the guided mode nature as its travels in waveguide bends structures. The results show
that a reasonable agreement between both theoretical approaches.
Offset effect on the S-Bend structure losses and optimization of its size for...IJECEIAES
The S-Bend structures are heavily exploited to join optical components. Reducing the power loss caused by the curve is the main objective in the design step of these components. However integrated optical circuits require S-Bend waveguide to be low loss and compact sized. In this paper, we present a contribution to link the curved structure to the straight waveguide by using the simulated bend function available in the Beam propagation tool of the Rsoft commercial software package. Simulation results confirm that this approach allows a reduction of the size of the curved structure with offset with relatively minimum of losses for photonic field.
A horn may be considered as a flared out waveguide. In this paper, a powerful electromagnetic simulator, 3D
EM solver WIPL-D software is used to design, analyse and optimize the dimensions of horn antenna which is
based on MOM solution for computations. The standard horn antenna at 10 GHz for 15dB gain is modelled and
the radiation pattern was observed. The horn antenna is optimized to achieve more than 20dB gain using
Genetic Algorithm, radiation patterns of the optimized horn antenna are also presented. Geometry of the horn
can be modelled by exploring the toolbar ‘symmetry’ option in WIPL-D. Design of X band Pyramidal Horn
Antenna is fabricated and measured using Network Analyzer.
This paper presents a trifocal Rotman Lens Design
approach. The effects of focal ratio and element spacing on
the performance of Rotman Lens are described. A three beam
prototype feeding 4 element antenna array working in L-band
has been simulated using RLD v1.7 software. Simulated
results show that the simulated lens has a return loss of –
12.4dB at 1.8GHz. Beam to array port phase error variation
with change in the focal ratio and element spacing has also
been investigated.
Circular polarization folded reflectarray antenna for 5G applicationsTELKOMNIKA JOURNAL
Fifth-generation (5G) is a wireless connection built specifically to keep up with the rapid increase
of devices that need a mobile internet connection. A system working on 5G band can provide higher
bandwidth and faster data rate as compared to fourth-generation (4G) band. Thus, an antenna with higher
gain and lower profile is required to support this system. On the other hand, the performance of circular
polarization antenna is better than linear polarization antenna due to its ability to accept wave from
different direction. In this project, a low-profile circular polarization folded reflectarray antenna with
operating frequency of 28 GHz is presented. This project is divided into two parts. In the first part, a linear
polarization folded reflectarray antenna is designed. In this second part, a meander lines polarizer is used
to convert the linear polarization antenna to circular polarization antenna. The antenna is fed by a linear
polarized waveguide. Each radiating element of the antenna is in rectangular shape. The size of
the radiating elements are selected according to obtain required phase delay to form a planar phase front
in the far-field distance. Both of the antennas are simulated by using Computer Simulation Technology
(CST) software. Finally, the results show excellent performances with 16.81 dB directivity and 1.49 dB
axial ratio at 28 GHz. Thus, the antenna is very suitable for 5G applications.
Optical Wireless Communication (OWC) has attracted the researchers as an alternative broadband technology for wireless communication. In OWC optical beams are used to transport data through atmosphere or even vacuum. We have proposed an OWC model and analyze the transmission performance of OW channel for indoor/ outdoor application. The performance has been judged on the basis of key parameters like BER and OSNR. A theoretical model has also been presented and validated by the simulation results. The proposed OWC channel was simulated in Optisystem which is a powerful tool of Optical communication System
Design of Miniaturized Multiband Patch Antenna Using CSRR for WLAN/WiMAX Appl...TELKOMNIKA JOURNAL
A novel miniaturized multiband, single-feed microstrip patch antenna is presented in this paper for
WLAN and WiMAX applications. Both size reduction and multiband are obtained by etching the Multiple
Complementary Split Ring Resonators (MC-SRR) on the ground plane of the normal patch antenna. At
first, the normal patch antenna produces a single band of 5.15 GHz; 200 MHz (5.0500~5.2499).
Subsequently, a Single Circular Split Ring Resonator (SC-SRR) is etched on the ground plane and
produces a triple band of: 3.25 GHz; 288 MHz (3.1085~3.3964), 4.5 GHz; 101.3 MHz (4.4488~4.5501),
and 5.22 GHz; 220 MHz (5.1191~5.3400) and Double Single Circular Split Ring Resonator (DC-MCSRR)
with: 2.99 GHz; 60.7 MHz (2.9574~3.0181), 3.57 GHz; 324.7 MHz (3.4065~3.7312), and 5.1413 GHz;
115.4 MHz (5.0817~5.1971). The working bandwidths cover the desired frequency bands of WLAN
5.2 GHz and WiMAX 3.3/3.5 GHz. The proposed (MC-SRR) antenna can be employed to wireless
communication systems due to its simplicity in design, compactness and miniaturization.
Time Domain Modelling of Optical Add-drop filter based on Microcavity Ring Re...iosrjce
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Band-pass filter based on complementary split ring resonatorTELKOMNIKA JOURNAL
This letter presents a new circuit of the band-pass filter designed by using microstrip technology. Based on complementary split ring resonator and various series of optimization technic and a specific design method, a miniature band-pass filter with excellent electrical performances is achieved. First of all, the metamaterial unit cell is studied to obtain a desired resonant frequency and it is implemented in the ground plan in order to increase the characteristics of the bandpass behavior and decrease its operating frequencies. This proposed circuit is designed on an FR-4 substrate having a relative permittivity of 4.4 tangential losses of 0.025 and thickness of 1.6 mm. This filter is developed by using CST Microwave. The obtained features allow this filter to be used in diverse wireless applications such as IMT-E and WiMax.
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.
Similar to Design of wideband Rotman lens for wireless applications (20)
Amazon products reviews classification based on machine learning, deep learni...TELKOMNIKA JOURNAL
In recent times, the trend of online shopping through e-commerce stores and websites has grown to a huge extent. Whenever a product is purchased on an e-commerce platform, people leave their reviews about the product. These reviews are very helpful for the store owners and the product’s manufacturers for the betterment of their work process as well as product quality. An automated system is proposed in this work that operates on two datasets D1 and D2 obtained from Amazon. After certain preprocessing steps, N-gram and word embedding-based features are extracted using term frequency-inverse document frequency (TF-IDF), bag of words (BoW) and global vectors (GloVe), and Word2vec, respectively. Four machine learning (ML) models support vector machines (SVM), logistic regression (RF), logistic regression (LR), multinomial Naïve Bayes (MNB), two deep learning (DL) models convolutional neural network (CNN), long-short term memory (LSTM), and standalone bidirectional encoder representations (BERT) are used to classify reviews as either positive or negative. The results obtained by the standard ML, DL models and BERT are evaluated using certain performance evaluation measures. BERT turns out to be the best-performing model in the case of D1 with an accuracy of 90% on features derived by word embedding models while the CNN provides the best accuracy of 97% upon word embedding features in the case of D2. The proposed model shows better overall performance on D2 as compared to D1.
Design, simulation, and analysis of microstrip patch antenna for wireless app...TELKOMNIKA JOURNAL
In this study, a microstrip patch antenna that works at 3.6 GHz was built and tested to see how well it works. In this work, Rogers RT/Duroid 5880 has been used as the substrate material, with a dielectric permittivity of 2.2 and a thickness of 0.3451 mm; it serves as the base for the examined antenna. The computer simulation technology (CST) studio suite is utilized to show the recommended antenna design. The goal of this study was to get a more extensive transmission capacity, a lower voltage standing wave ratio (VSWR), and a lower return loss, but the main goal was to get a higher gain, directivity, and efficiency. After simulation, the return loss, gain, directivity, bandwidth, and efficiency of the supplied antenna are found to be -17.626 dB, 9.671 dBi, 9.924 dBi, 0.2 GHz, and 97.45%, respectively. Besides, the recreation uncovered that the transfer speed side-lobe level at phi was much better than those of the earlier works, at -28.8 dB, respectively. Thus, it makes a solid contender for remote innovation and more robust communication.
Design and simulation an optimal enhanced PI controller for congestion avoida...TELKOMNIKA JOURNAL
In this paper, snake optimization algorithm (SOA) is used to find the optimal gains of an enhanced controller for controlling congestion problem in computer networks. M-file and Simulink platform is adopted to evaluate the response of the active queue management (AQM) system, a comparison with two classical controllers is done, all tuned gains of controllers are obtained using SOA method and the fitness function chose to monitor the system performance is the integral time absolute error (ITAE). Transient analysis and robust analysis is used to show the proposed controller performance, two robustness tests are applied to the AQM system, one is done by varying the size of queue value in different period and the other test is done by changing the number of transmission control protocol (TCP) sessions with a value of ± 20% from its original value. The simulation results reflect a stable and robust behavior and best performance is appeared clearly to achieve the desired queue size without any noise or any transmission problems.
Improving the detection of intrusion in vehicular ad-hoc networks with modifi...TELKOMNIKA JOURNAL
Vehicular ad-hoc networks (VANETs) are wireless-equipped vehicles that form networks along the road. The security of this network has been a major challenge. The identity-based cryptosystem (IBC) previously used to secure the networks suffers from membership authentication security features. This paper focuses on improving the detection of intruders in VANETs with a modified identity-based cryptosystem (MIBC). The MIBC is developed using a non-singular elliptic curve with Lagrange interpolation. The public key of vehicles and roadside units on the network are derived from number plates and location identification numbers, respectively. Pseudo-identities are used to mask the real identity of users to preserve their privacy. The membership authentication mechanism ensures that only valid and authenticated members of the network are allowed to join the network. The performance of the MIBC is evaluated using intrusion detection ratio (IDR) and computation time (CT) and then validated with the existing IBC. The result obtained shows that the MIBC recorded an IDR of 99.3% against 94.3% obtained for the existing identity-based cryptosystem (EIBC) for 140 unregistered vehicles attempting to intrude on the network. The MIBC shows lower CT values of 1.17 ms against 1.70 ms for EIBC. The MIBC can be used to improve the security of VANETs.
Conceptual model of internet banking adoption with perceived risk and trust f...TELKOMNIKA JOURNAL
Understanding the primary factors of internet banking (IB) acceptance is critical for both banks and users; nevertheless, our knowledge of the role of users’ perceived risk and trust in IB adoption is limited. As a result, we develop a conceptual model by incorporating perceived risk and trust into the technology acceptance model (TAM) theory toward the IB. The proper research emphasized that the most essential component in explaining IB adoption behavior is behavioral intention to use IB adoption. TAM is helpful for figuring out how elements that affect IB adoption are connected to one another. According to previous literature on IB and the use of such technology in Iraq, one has to choose a theoretical foundation that may justify the acceptance of IB from the customer’s perspective. The conceptual model was therefore constructed using the TAM as a foundation. Furthermore, perceived risk and trust were added to the TAM dimensions as external factors. The key objective of this work was to extend the TAM to construct a conceptual model for IB adoption and to get sufficient theoretical support from the existing literature for the essential elements and their relationships in order to unearth new insights about factors responsible for IB adoption.
Efficient combined fuzzy logic and LMS algorithm for smart antennaTELKOMNIKA JOURNAL
The smart antennas are broadly used in wireless communication. The least mean square (LMS) algorithm is a procedure that is concerned in controlling the smart antenna pattern to accommodate specified requirements such as steering the beam toward the desired signal, in addition to placing the deep nulls in the direction of unwanted signals. The conventional LMS (C-LMS) has some drawbacks like slow convergence speed besides high steady state fluctuation error. To overcome these shortcomings, the present paper adopts an adaptive fuzzy control step size least mean square (FC-LMS) algorithm to adjust its step size. Computer simulation outcomes illustrate that the given model has fast convergence rate as well as low mean square error steady state.
Design and implementation of a LoRa-based system for warning of forest fireTELKOMNIKA JOURNAL
This paper presents the design and implementation of a forest fire monitoring and warning system based on long range (LoRa) technology, a novel ultra-low power consumption and long-range wireless communication technology for remote sensing applications. The proposed system includes a wireless sensor network that records environmental parameters such as temperature, humidity, wind speed, and carbon dioxide (CO2) concentration in the air, as well as taking infrared photos.The data collected at each sensor node will be transmitted to the gateway via LoRa wireless transmission. Data will be collected, processed, and uploaded to a cloud database at the gateway. An Android smartphone application that allows anyone to easily view the recorded data has been developed. When a fire is detected, the system will sound a siren and send a warning message to the responsible personnel, instructing them to take appropriate action. Experiments in Tram Chim Park, Vietnam, have been conducted to verify and evaluate the operation of the system.
Wavelet-based sensing technique in cognitive radio networkTELKOMNIKA JOURNAL
Cognitive radio is a smart radio that can change its transmitter parameter based on interaction with the environment in which it operates. The demand for frequency spectrum is growing due to a big data issue as many Internet of Things (IoT) devices are in the network. Based on previous research, most frequency spectrum was used, but some spectrums were not used, called spectrum hole. Energy detection is one of the spectrum sensing methods that has been frequently used since it is easy to use and does not require license users to have any prior signal understanding. But this technique is incapable of detecting at low signal-to-noise ratio (SNR) levels. Therefore, the wavelet-based sensing is proposed to overcome this issue and detect spectrum holes. The main objective of this work is to evaluate the performance of wavelet-based sensing and compare it with the energy detection technique. The findings show that the percentage of detection in wavelet-based sensing is 83% higher than energy detection performance. This result indicates that the wavelet-based sensing has higher precision in detection and the interference towards primary user can be decreased.
A novel compact dual-band bandstop filter with enhanced rejection bandsTELKOMNIKA JOURNAL
In this paper, we present the design of a new wide dual-band bandstop filter (DBBSF) using nonuniform transmission lines. The method used to design this filter is to replace conventional uniform transmission lines with nonuniform lines governed by a truncated Fourier series. Based on how impedances are profiled in the proposed DBBSF structure, the fractional bandwidths of the two 10 dB-down rejection bands are widened to 39.72% and 52.63%, respectively, and the physical size has been reduced compared to that of the filter with the uniform transmission lines. The results of the electromagnetic (EM) simulation support the obtained analytical response and show an improved frequency behavior.
Deep learning approach to DDoS attack with imbalanced data at the application...TELKOMNIKA JOURNAL
A distributed denial of service (DDoS) attack is where one or more computers attack or target a server computer, by flooding internet traffic to the server. As a result, the server cannot be accessed by legitimate users. A result of this attack causes enormous losses for a company because it can reduce the level of user trust, and reduce the company’s reputation to lose customers due to downtime. One of the services at the application layer that can be accessed by users is a web-based lightweight directory access protocol (LDAP) service that can provide safe and easy services to access directory applications. We used a deep learning approach to detect DDoS attacks on the CICDDoS 2019 dataset on a complex computer network at the application layer to get fast and accurate results for dealing with unbalanced data. Based on the results obtained, it is observed that DDoS attack detection using a deep learning approach on imbalanced data performs better when implemented using synthetic minority oversampling technique (SMOTE) method for binary classes. On the other hand, the proposed deep learning approach performs better for detecting DDoS attacks in multiclass when implemented using the adaptive synthetic (ADASYN) method.
The appearance of uncertainties and disturbances often effects the characteristics of either linear or nonlinear systems. Plus, the stabilization process may be deteriorated thus incurring a catastrophic effect to the system performance. As such, this manuscript addresses the concept of matching condition for the systems that are suffering from miss-match uncertainties and exogeneous disturbances. The perturbation towards the system at hand is assumed to be known and unbounded. To reach this outcome, uncertainties and their classifications are reviewed thoroughly. The structural matching condition is proposed and tabulated in the proposition 1. Two types of mathematical expressions are presented to distinguish the system with matched uncertainty and the system with miss-matched uncertainty. Lastly, two-dimensional numerical expressions are provided to practice the proposed proposition. The outcome shows that matching condition has the ability to change the system to a design-friendly model for asymptotic stabilization.
Implementation of FinFET technology based low power 4×4 Wallace tree multipli...TELKOMNIKA JOURNAL
Many systems, including digital signal processors, finite impulse response (FIR) filters, application-specific integrated circuits, and microprocessors, use multipliers. The demand for low power multipliers is gradually rising day by day in the current technological trend. In this study, we describe a 4×4 Wallace multiplier based on a carry select adder (CSA) that uses less power and has a better power delay product than existing multipliers. HSPICE tool at 16 nm technology is used to simulate the results. In comparison to the traditional CSA-based multiplier, which has a power consumption of 1.7 µW and power delay product (PDP) of 57.3 fJ, the results demonstrate that the Wallace multiplier design employing CSA with first zero finding logic (FZF) logic has the lowest power consumption of 1.4 µW and PDP of 27.5 fJ.
Evaluation of the weighted-overlap add model with massive MIMO in a 5G systemTELKOMNIKA JOURNAL
The flaw in 5G orthogonal frequency division multiplexing (OFDM) becomes apparent in high-speed situations. Because the doppler effect causes frequency shifts, the orthogonality of OFDM subcarriers is broken, lowering both their bit error rate (BER) and throughput output. As part of this research, we use a novel design that combines massive multiple input multiple output (MIMO) and weighted overlap and add (WOLA) to improve the performance of 5G systems. To determine which design is superior, throughput and BER are calculated for both the proposed design and OFDM. The results of the improved system show a massive improvement in performance ver the conventional system and significant improvements with massive MIMO, including the best throughput and BER. When compared to conventional systems, the improved system has a throughput that is around 22% higher and the best performance in terms of BER, but it still has around 25% less error than OFDM.
Reflector antenna design in different frequencies using frequency selective s...TELKOMNIKA JOURNAL
In this study, it is aimed to obtain two different asymmetric radiation patterns obtained from antennas in the shape of the cross-section of a parabolic reflector (fan blade type antennas) and antennas with cosecant-square radiation characteristics at two different frequencies from a single antenna. For this purpose, firstly, a fan blade type antenna design will be made, and then the reflective surface of this antenna will be completed to the shape of the reflective surface of the antenna with the cosecant-square radiation characteristic with the frequency selective surface designed to provide the characteristics suitable for the purpose. The frequency selective surface designed and it provides the perfect transmission as possible at 4 GHz operating frequency, while it will act as a band-quenching filter for electromagnetic waves at 5 GHz operating frequency and will be a reflective surface. Thanks to this frequency selective surface to be used as a reflective surface in the antenna, a fan blade type radiation characteristic at 4 GHz operating frequency will be obtained, while a cosecant-square radiation characteristic at 5 GHz operating frequency will be obtained.
Reagentless iron detection in water based on unclad fiber optical sensorTELKOMNIKA JOURNAL
A simple and low-cost fiber based optical sensor for iron detection is demonstrated in this paper. The sensor head consist of an unclad optical fiber with the unclad length of 1 cm and it has a straight structure. Results obtained shows a linear relationship between the output light intensity and iron concentration, illustrating the functionality of this iron optical sensor. Based on the experimental results, the sensitivity and linearity are achieved at 0.0328/ppm and 0.9824 respectively at the wavelength of 690 nm. With the same wavelength, other performance parameters are also studied. Resolution and limit of detection (LOD) are found to be 0.3049 ppm and 0.0755 ppm correspondingly. This iron sensor is advantageous in that it does not require any reagent for detection, enabling it to be simpler and cost-effective in the implementation of the iron sensing.
Impact of CuS counter electrode calcination temperature on quantum dot sensit...TELKOMNIKA JOURNAL
In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime.
In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime.
A progressive learning for structural tolerance online sequential extreme lea...TELKOMNIKA JOURNAL
This article discusses the progressive learning for structural tolerance online sequential extreme learning machine (PSTOS-ELM). PSTOS-ELM can save robust accuracy while updating the new data and the new class data on the online training situation. The robustness accuracy arises from using the householder block exact QR decomposition recursive least squares (HBQRD-RLS) of the PSTOS-ELM. This method is suitable for applications that have data streaming and often have new class data. Our experiment compares the PSTOS-ELM accuracy and accuracy robustness while data is updating with the batch-extreme learning machine (ELM) and structural tolerance online sequential extreme learning machine (STOS-ELM) that both must retrain the data in a new class data case. The experimental results show that PSTOS-ELM has accuracy and robustness comparable to ELM and STOS-ELM while also can update new class data immediately.
Electroencephalography-based brain-computer interface using neural networksTELKOMNIKA JOURNAL
This study aimed to develop a brain-computer interface that can control an electric wheelchair using electroencephalography (EEG) signals. First, we used the Mind Wave Mobile 2 device to capture raw EEG signals from the surface of the scalp. The signals were transformed into the frequency domain using fast Fourier transform (FFT) and filtered to monitor changes in attention and relaxation. Next, we performed time and frequency domain analyses to identify features for five eye gestures: opened, closed, blink per second, double blink, and lookup. The base state was the opened-eyes gesture, and we compared the features of the remaining four action gestures to the base state to identify potential gestures. We then built a multilayer neural network to classify these features into five signals that control the wheelchair’s movement. Finally, we designed an experimental wheelchair system to test the effectiveness of the proposed approach. The results demonstrate that the EEG classification was highly accurate and computationally efficient. Moreover, the average performance of the brain-controlled wheelchair system was over 75% across different individuals, which suggests the feasibility of this approach.
Adaptive segmentation algorithm based on level set model in medical imagingTELKOMNIKA JOURNAL
For image segmentation, level set models are frequently employed. It offer best solution to overcome the main limitations of deformable parametric models. However, the challenge when applying those models in medical images stills deal with removing blurs in image edges which directly affects the edge indicator function, leads to not adaptively segmenting images and causes a wrong analysis of pathologies wich prevents to conclude a correct diagnosis. To overcome such issues, an effective process is suggested by simultaneously modelling and solving systems’ two-dimensional partial differential equations (PDE). The first PDE equation allows restoration using Euler’s equation similar to an anisotropic smoothing based on a regularized Perona and Malik filter that eliminates noise while preserving edge information in accordance with detected contours in the second equation that segments the image based on the first equation solutions. This approach allows developing a new algorithm which overcome the studied model drawbacks. Results of the proposed method give clear segments that can be applied to any application. Experiments on many medical images in particular blurry images with high information losses, demonstrate that the developed approach produces superior segmentation results in terms of quantity and quality compared to other models already presented in previeous works.
Automatic channel selection using shuffled frog leaping algorithm for EEG bas...TELKOMNIKA JOURNAL
Drug addiction is a complex neurobiological disorder that necessitates comprehensive treatment of both the body and mind. It is categorized as a brain disorder due to its impact on the brain. Various methods such as electroencephalography (EEG), functional magnetic resonance imaging (FMRI), and magnetoencephalography (MEG) can capture brain activities and structures. EEG signals provide valuable insights into neurological disorders, including drug addiction. Accurate classification of drug addiction from EEG signals relies on appropriate features and channel selection. Choosing the right EEG channels is essential to reduce computational costs and mitigate the risk of overfitting associated with using all available channels. To address the challenge of optimal channel selection in addiction detection from EEG signals, this work employs the shuffled frog leaping algorithm (SFLA). SFLA facilitates the selection of appropriate channels, leading to improved accuracy. Wavelet features extracted from the selected input channel signals are then analyzed using various machine learning classifiers to detect addiction. Experimental results indicate that after selecting features from the appropriate channels, classification accuracy significantly increased across all classifiers. Particularly, the multi-layer perceptron (MLP) classifier combined with SFLA demonstrated a remarkable accuracy improvement of 15.78% while reducing time complexity.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
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/
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
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.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
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Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
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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.
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TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
AIRCRAFT GENERAL
The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
The family offers a choice of engines
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beam countor. While the second objective is proposed an implementation of microstrip Rotman
lens to scan the azimuth plane with coverage angle ±26o and the operating frequency of
the design is selected to be in Industrial, Scientific, and Medical (ISM) radio band.
In general, the structure of the lens is a multiport device with three types of ports as
shown in Figure 1. Firstly, the beam ports are the input ports to the lens cavity which is
the desired frequency will be applied. Secondly, the receive ports that receive the energy from
the beam ports to deliver it to the connected array elements of the transmission line. Finally,
he side wall of the cavity lens will be terminated by the dummy ports and 50Ω loads to absorb
energy and reduce the reflections inside the lens cavity which are affected directly
thephase performance.
Figure 1. Rotman lens geometry [10]
2. Research Method
This section of the study will be divided into three subsections. In the first section,
Rotman lens design equation and parameter definition will be explored. While in the second
section, parametric study for lens design procedure beside its relation to the phase error will be
discussed in details. Finally, the proposed lens design at 2.45 GHz and a final lens CST model
will be implemented and explained.
2.1. Rotman Lens Parameters and Design Equations
Beamforming techniques in a linear phased array system are depending mainly on
the linear phase shift which feeds the radiated elements in ordered to form the radiation pattern
in the desired angle [6]. The standard excitation system provides only one excitation port with
specific magnitude and phase. In order to produce a multi-phase shift a BFNs is applied.
The Microstrip Rotman lens model is a structure can provide a progressive phase shift to
the radiation pattern, the position of the three focal points (F1, F2, and F3) on the beam contour
has theoretically free phase error with a unique subtended angle (α). These focal points are
placed in the beam contour.
The shape of the beam contour can be circular or elliptical depends on the lens shape
and the phase error level. While receiving ports placed on the receive contour at (X, Y)
coordinate. Array elements connected to receive contour by transmission lines with length (W).
The length of transmission lines saves the phase reach each array element. The distance
between adjacent array elements is (d). The beam width of the radiation pattern and
the sidelobe level can be controlled by adjusting (d) value [23]. However, in this study, the lens
modeled using microstrip transmission line theory, but it can be designed using different
materials permittivity (εr) and (εe). The subtended angle (α) can be the difference from a
radiation beam angle (Ψ) in order to give more freedom design ability [14, 15, 24]. The final lens
structure will have low impedance due to its large area compared with the 50Ω transmission
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line. In order to balance the impedance between the lens cavity and a transmission line, a
transformation impedance must be used. In the general tapering line between the transmission
line and the lens cavity will be used to decrease the discontinuity and match the impedance of
the lens cavity with 50Ω. An optimization process will be carried out to the length of taper to
determine the best return loss of the ports in the range of operating frequency. However, a
quarter wavelength multi-sections lines can be used to match between the lens cavity and
transmission line. The length sections can be determined using a standing wave pattern [25].
By equalizing the path from the three focal points to the phase front of the lens
the design equations can be derived as follows [26]:
2
2 2
3
3
1
2 2 2 2
2
2 2
2 2 2 2 2 4
2
- - 4
(1)
2
sin (1- )
(2)
2 ( cos -1) cos -1
sin
(1- ) (3)
sin
1- 2 2(1- ) (1- )
: 1- ( ) - , -2 -
1- 1- (1- )
1
(- - - )
1- 1- 4(1- )
e
r
e
r r
e
r r
rr r
b b a c
w
a
Y w
x
Y w
y
f
S
Where a b
C C C
S S S
c
C C C
=
= +
=
= = + +
= +
32
1 1
sin
, , sin , cos
sin
r
Yf
S C
f f
= = = =
where the values: x, y, and w are normalized to on-focal length axis f1.
2.2. Parametric Study for Lens Geometry
Rotman lens is a structure used to achieve a linear phase shift to radiation elements in
order to form different beams to scan specific angles. So, the design parameters related directly
to the phase error. In this section, a parametric study to the lens design parameters will be
conducted besides its relation to the phase will be explained. The relation between the off-focal
physical length (f2) and on-focal physical length (f1) is the parameter (β) which consider
the main optimization factor of the phase error. It is realized from a parametric investigation that
the beam contour becomes flatter and the receiver contour shrinks when the value of (β)
increased as Figure 2 described.
Figure 2. Lens contour shape versus β
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The tri-focal Rotman lens contains three focal points with zero phase error, however, to
achieve more than three scan steps a nonfocal point must be introduced. These non-focal
points have a phase error, on other terms, non-focal points do not apply the path length
equalities which is considered the first step to drive lens design equations [27]. The phase error
of multi (β) is examined as Figure 3 described. The area under the curve indicates that
the maximum phase error at β=0.85.
According to the parametric study, the beam contour circular shape has a small
difference phase error value compared with the elliptical one as Figure 4 described, which (e=0)
is referred to circular beam contour. However, the elliptical shape can be used in the large
model to point the beam taper direction to receiver ports and reduce phase error [24].
Figure 3. Maximum phase error versus beta parameter
Figure 4. The eccentricity of beam contour versus phase error
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Finally, the relation between aperture length (D) and focal length (f1) is considered an
important factor in the phase error optimization as Figure 5 explained. It can be noted that
the length of (D) related to aperture size of the lens and the value of (f1) is a normalized factor
effect to the overall dimensions of the lens besides the bandwidth of operating frequency.
Figure 5. f1/D versus phase error
2.3. Simulation and Measurements Results
In this section, Microstrip Rotman lens will be constructed using the design parameters
explained in Table 1. The lens geometry is determined using MATLAB and the model is
simulated using CST Microwave Studio. The calculated beam lens and receiver contour besides
the port locations are explained in Figure 6.
Table 1. Lens design specifications
Design variable Value Design variable Value
No. Of beam ports 5 Focal length (f1) 1.45 λg
No. Of antenna ports 4 Displacement, distance (d) 0.43 λ
No. Of dummy ports 8 Substrate thickness 1.565 mm
Scan angle (α) ±26o
Length 209.52 mm
Relative permittivity (εr) 4.2 Width 203.62 mm
Loss tangent 0.025
Center frequency 2.45 GHz
Copper thickness 0.035 mm
Tapering ports will be used in the final lens model in order to guarantee a smooth
energy transition from input ports to the lens cavity and receiver ports to radiated elements.
The optimization process is conducted to achieve an acceptable return loss for tapering
ports [28]. Eight tapered dummy ports with 50 Ω load will terminate the side wall in order to
reduce the reflections inside the lens cavity and the phase performance. The full lens structure
with five beam port order (1-5), four receivers (6-7) and eight dummy ports (10-17) is shown
in Figure 7. It can be concluded from the lens geometry that the number of beam ports is related
to the scan steps and the number of the receiver ports is proportional with radiated elements, on
other words, when the number of radiated elements is increased a high gain radiation beam
will be achieved.
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Figure 6. Lens geometry Figure 7. Lens structure CST model
3. Results and Analysis
In this section, the fabrication process for the CST lens model is conducted. While
the simulation results for the beam ports return loss and the coupling including phase and
energy between beam ports and receive ports obtained by Microwave CST Studio are validated
by measurements. Finally, the radiation pattern using array elements will be tested.
The lens performance is related to the return loss and phase performance. The full
matrix s-parameters are tested using CST Microwave Studio and validated by vector network
analyzer measurements. The return loss of beams ports is shown in Figure 8. An acceptable
return loss below -10 dB in the bandwidth range (2.1811-2.774 GHz) is achieved for beam
ports. It can be noted that only three beam ports are shown in Figure 8 due to symmetrical
geometry. In addition as a comparable to the lens reported in [29], it can be realized the effect of
the lens dimension specially the on-focal length to the bandwidth range as a results of
minimizing the focal length the bandwidth became narrower.
Figure 8. Beam ports return loss
The linear phase shift is the main objective in the lens to direct the beam into angles.
The linearity in the phase shift when beam ports are excited by 2.45 GHz is shown in Figure 9.
It can be noted that the phase shift for the port3 across the receive ports close to being zero in
order to form the radiation beam at a zero scan angle as will be explained in the next section.
Otherwise, the phase shift for the port two and three is increased across the receive ports.
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Coupling between beam ports and receive ports are an indication about the energy
reached to the radiation elements from the excitation ports. The results indicated that an even
energy is distributed across receive ports when beam ports is excited at 2.45 GHz with a
maximum fluctuation about 3 dB as shown in Figure 10.
Figure 9. Phase shift for beam
ports at 2.45 GHz
Figure 10. Coupling magnitude across receive
ports at 2.45GHz
In order to test the radiation pattern of the lens four microstrip patch antenna with center
frequency at 2.45 GHz are designed and fabricated to connect it to the lens by the right angle
SMA connector. The full beamforming system is described in Figure 11. After measurements of
the scattering parameters of the fabricated lens, the radiation pattern measurements will be
carried out in order to realize the beams and the scanning angle switching. The measurement is
conducted in the anechoic chamber and the setup is shown in Figure 12.
Figure 11. Full system beamforming: (a) top view (b) front view
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Each beam port is excited by 2.45 GHz and all the other ports are terminated with 50Ω
loads during the measurements. The simulation and measurement result of the radiation pattern
for the five scanning beams are shown in Figure 13. It can be noted that the desired coverage
angle ±26o are achieved in the azimuth plane with five scanning steps.
Figure 12. Measurements set up for
radiation pattern
Figure 13. Radiation pattern for beamforming
system at 2.45 GHz
4. Conclusion
A compact microstrip Rotman lens for wireless applications is proposed in this study to
feed four element array and provide five scanning beams. A numerical parametric examination
of the lens design structure to achieve low phase error for lens shape contour, relation between
focal length and aperture size, and phase optimization factor β was applied. Eccentricity showed
small effect to the phase error while minimum β provide maximum phase error for the selected
lens specification. The proposed lens model is fabricated using FR-4 with a compact area of
209.52*203.62*1.6 mm3. Five switching beams in azimuth plane are simulated and measured
by excitation 2.45 GHz for each beam port. Five beams are generated to cover ±26o using four
patch antenna. Besides, validation between simulation results using CST Microwave Studio and
measurements is carried out for return loss, phase shifting, radiation pattern, and energy
coupling between input ports and output ports. An agreement between numerical design
procedures and measurements is achieved.
ACKNOWLEDGEMENTS
The authors would like to acknowledge ORICC Universiti Tun Hussein Onn Malaysia
(UTHM) for supporting this work. This work was supported by research grants TIER 1
(vot no: U860).
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