Abstract
In this work, many techniques are suggested and analyses for
rectangular microstrip antenna (RMSA) operating in X-band for 10 GHz
center frequency. These approaches are: lowering quality factor, shifting
feeding point , using reactive loading and modification of the patch shape.
The design of a RMSA is made to several dielectric materials, and the
selection is based upon which material gives a better antenna performance
with reduced surface wave loss. Duroid 5880 and Quartz are the best materials
for proposed design to achieve a broader Bandwidth (BW) and better
mechanical characteristics than using air. The overall antenna BW for RMSA
is increased by 11.6 % with Duroid 5880 with shifted feeding point and with
central shorting pin (Reactive loading) while that for Quartz is 17.4 %.
Modification of patch shape with similar improving techniques gives an
overall increasing VSWR bandwidth of 26.2 % for Duroid 5880 and a
bandwidth of 30.9 % for Quartz. These results are simulated using Microwave
Office package version 3.22, 2000.
Average Channel Capacity of Amplify-and-forward MIMO/FSO Systems Over Atmosph...IJECEIAES
In amplify-and-forward (AF) relay channel, when the direct link between source and destination terminals is deeply faded, the signal from the source terminal to the destination terminal propagates through the relay terminals, each of which relays a signal received from the previous terminal to the next terminal in series. This paper, we theoretically analyze the performance of multiple-input multiple-output (MIMO) AF free-space optical (FSO) systems. The AF-MIMO/FSO average channel capacity (ACC), which is expressed in terms of average spectral efficiency (ASE) is derived taking into account the atmospheric turbulence effects on the MIMO/FSO channel. They are modeled by log-normal and the gamma-gamma distributions for the cases of weak-to-strong turbulence conditions. We extract closed form mathematical expression for the evaluation of the ACC and we quantitatively discuss the influence of turbulence strength, link distance, different number of relay stations and different MIMO configurations on it.
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.
A Leaky Wave Antenna Design Based on Half-mode Substrate Integrated Waveguide...IJECEIAES
A new type of leaky-wave antenna (LWA) using half-mode substrate integrated waveguide (HMSIW) as the base structure is proposed in this paper. The structure consists of an array of slot, antenna designed to operate in X band applications from 8 to 12 GHz. HMSIW preserves nearly all the advantages of SIW whereas its size is nearly reduced by half. The antenna radiates one main beam that can be steered from the backward to the forward direction by changing frequency.
Performance analysis of beam divergence propagation through rainwater and sno...journalBEEI
In the present work the future communication requirements need to fulfill with high data rate, FSO (free space optic) with it is tremendous potential is the solution. This research observed the effectiveness analysis of FSO systems by modifying one of the most important FSO parameters beam divergence, under the most affected weather attenuating condition Rainwater and snow pack. The simulation is obtained and analyzed under single channels CSRZ-FSO (carrier-suppressed return-to-zero/free space optical) systems having capacity of 40 Gbps between two transceivers with variable distance. The connection is presently under 5 meteorological turbulences (light rain, medium rain, wet snow, heavy rain and dry snow). The results show the heavy rain and dry snow have a very high attenuation carried out in terms of Q-factor. this result led us to conclude that small divergence offers significant performance improvement for FSO link and this performance decrease every time the beam divergence increase, Therefore, to build inexpensive and reliable transmission media, we go with new method that still in the experiment area called hybrid RF/FSO (radio frequency/free space optical) that compatible with atmospherically status.
A new look on CSI imperfection in downlink NOMA systemsjournalBEEI
Observing that cooperative scheme benefits to non-orthogonal multiple access (NOMA) systems, we focus on system performance analysis of downlink. However, spectrum efficiency is still high priority to be addressed in existing systems and hence this paper presents full-duplex enabling in NOMA systems. Other challenge needs be considered related to channel state information (CSI). In particular, we derive closedform expressions of outage probability for such NOMA systems under the presence of CSI imperfection. Furthermore, to fully exploit practical environment, we provide system model associated with Nakagami-m fading. The Monte-Carlo simulations are conducted to verify the exactness of considered systems.
3D FSS with multiple transmission zeros and pseudo elliptic responsejournalBEEI
The three-dimensional frequency selective surface (3D FSS) with band reject multiple transmission zeros and pseudo-elliptic response is designed from two-dimensional (2D) periodic array of shielded micro strip lines to realize wide out-of–band radio wave rejection. The 3D FSS array consists of multimode cavities whose coupling with air can be controlled to obtain a desired frequency range. The proposed FSS with shorting via to ground exhibits pseudo-elliptic band-reject response in the frequency range from 6GHz to 14GHz. As the plane wave of linear polarization incidents perpendicularly to the shielded micro strip line with perfect electric conductor (PEC) and perfect magnetic conductor (PMC) boundary walls, two quasi-TEM modes are obtained known as air mode and substrate mode. The first 3D FSS design is a combination of two or more resonators. Furthermore, second 3D FSS design with three shorting vias result more elliptic band reject frequency response and a pass band transmission pole. All in phase resonators of design give transmission poles and out of phase combination of resonators give transmission zeros respectively. The proposed 3D FSS is designed and simulated using Ansys HFSS software. These designs exhibit an improved performance for many practical applications such as antenna sub-reflector, and spatial filters.
STUDY OF ARRAY BI-CONICAL ANTENNA FOR DME APPLICATIONSijwmn
This paper introduces a new configuration of array bi-conical antenna to enhance the gain of an antenna for Distance Measuring Equipment (DME) avionic system. Due to its large size, the antenna can be placed in terrestrials DME stations. The antenna consists of the bi-conical elements placed in a linear configuration. The simulated maximum gain is 10.2dB, the antenna operates in the DME band (960 – 1215 MHz). Al the simulations are performed with CADFEKO a Method of Moments based Solver.
Average Channel Capacity of Amplify-and-forward MIMO/FSO Systems Over Atmosph...IJECEIAES
In amplify-and-forward (AF) relay channel, when the direct link between source and destination terminals is deeply faded, the signal from the source terminal to the destination terminal propagates through the relay terminals, each of which relays a signal received from the previous terminal to the next terminal in series. This paper, we theoretically analyze the performance of multiple-input multiple-output (MIMO) AF free-space optical (FSO) systems. The AF-MIMO/FSO average channel capacity (ACC), which is expressed in terms of average spectral efficiency (ASE) is derived taking into account the atmospheric turbulence effects on the MIMO/FSO channel. They are modeled by log-normal and the gamma-gamma distributions for the cases of weak-to-strong turbulence conditions. We extract closed form mathematical expression for the evaluation of the ACC and we quantitatively discuss the influence of turbulence strength, link distance, different number of relay stations and different MIMO configurations on it.
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.
A Leaky Wave Antenna Design Based on Half-mode Substrate Integrated Waveguide...IJECEIAES
A new type of leaky-wave antenna (LWA) using half-mode substrate integrated waveguide (HMSIW) as the base structure is proposed in this paper. The structure consists of an array of slot, antenna designed to operate in X band applications from 8 to 12 GHz. HMSIW preserves nearly all the advantages of SIW whereas its size is nearly reduced by half. The antenna radiates one main beam that can be steered from the backward to the forward direction by changing frequency.
Performance analysis of beam divergence propagation through rainwater and sno...journalBEEI
In the present work the future communication requirements need to fulfill with high data rate, FSO (free space optic) with it is tremendous potential is the solution. This research observed the effectiveness analysis of FSO systems by modifying one of the most important FSO parameters beam divergence, under the most affected weather attenuating condition Rainwater and snow pack. The simulation is obtained and analyzed under single channels CSRZ-FSO (carrier-suppressed return-to-zero/free space optical) systems having capacity of 40 Gbps between two transceivers with variable distance. The connection is presently under 5 meteorological turbulences (light rain, medium rain, wet snow, heavy rain and dry snow). The results show the heavy rain and dry snow have a very high attenuation carried out in terms of Q-factor. this result led us to conclude that small divergence offers significant performance improvement for FSO link and this performance decrease every time the beam divergence increase, Therefore, to build inexpensive and reliable transmission media, we go with new method that still in the experiment area called hybrid RF/FSO (radio frequency/free space optical) that compatible with atmospherically status.
A new look on CSI imperfection in downlink NOMA systemsjournalBEEI
Observing that cooperative scheme benefits to non-orthogonal multiple access (NOMA) systems, we focus on system performance analysis of downlink. However, spectrum efficiency is still high priority to be addressed in existing systems and hence this paper presents full-duplex enabling in NOMA systems. Other challenge needs be considered related to channel state information (CSI). In particular, we derive closedform expressions of outage probability for such NOMA systems under the presence of CSI imperfection. Furthermore, to fully exploit practical environment, we provide system model associated with Nakagami-m fading. The Monte-Carlo simulations are conducted to verify the exactness of considered systems.
3D FSS with multiple transmission zeros and pseudo elliptic responsejournalBEEI
The three-dimensional frequency selective surface (3D FSS) with band reject multiple transmission zeros and pseudo-elliptic response is designed from two-dimensional (2D) periodic array of shielded micro strip lines to realize wide out-of–band radio wave rejection. The 3D FSS array consists of multimode cavities whose coupling with air can be controlled to obtain a desired frequency range. The proposed FSS with shorting via to ground exhibits pseudo-elliptic band-reject response in the frequency range from 6GHz to 14GHz. As the plane wave of linear polarization incidents perpendicularly to the shielded micro strip line with perfect electric conductor (PEC) and perfect magnetic conductor (PMC) boundary walls, two quasi-TEM modes are obtained known as air mode and substrate mode. The first 3D FSS design is a combination of two or more resonators. Furthermore, second 3D FSS design with three shorting vias result more elliptic band reject frequency response and a pass band transmission pole. All in phase resonators of design give transmission poles and out of phase combination of resonators give transmission zeros respectively. The proposed 3D FSS is designed and simulated using Ansys HFSS software. These designs exhibit an improved performance for many practical applications such as antenna sub-reflector, and spatial filters.
STUDY OF ARRAY BI-CONICAL ANTENNA FOR DME APPLICATIONSijwmn
This paper introduces a new configuration of array bi-conical antenna to enhance the gain of an antenna for Distance Measuring Equipment (DME) avionic system. Due to its large size, the antenna can be placed in terrestrials DME stations. The antenna consists of the bi-conical elements placed in a linear configuration. The simulated maximum gain is 10.2dB, the antenna operates in the DME band (960 – 1215 MHz). Al the simulations are performed with CADFEKO a Method of Moments based Solver.
Impact of Using Modified Open Area Okumura-Hata Propagation Model in Determin...IJMERJOURNAL
ABSTRACT: This paper examines the applicability of the Okumura - Hata model in Malaysia in GSM frequency band. The study was carried out in the open area only since measurements provided from Malaysia Mobile were about the open areas. The mean square error (MSE) was calculated between measured path loss values and those predicted on basis of Okumura-Hata model for an open area. The MSE is up to 6dB, which is an acceptable value for the signal prediction. Therefore, the model gave a significant difference in an open area that allowed necessary changes to be introduced in the model. That error was minimized by subtracting the calculated MSE (15.31dB) from the original equation of open area for Okumura-Hata model. Modified equation was also verified for another cell in an open area in Malaysia and gave acceptable results.
A design of triple band slot loaded circular microstrip antenna for c- and x-...eSAT 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
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.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
In this paper, a low pass filter based on T-Shaped resonator is presented. The T-Shaped resonator consists of meandered lines and rectangular patches. Also, the LC model and transfer function of the proposed resonator is presented. For suppression of spurious harmonics, a bandstop structure consists of hexangular patches and open stubs has been utilized. Finally, the wide stopband microstrip lowpass filter with cutoff frequency 2.72 GHz has been simulated, fabricated and measured. The LPF has good characteristics such as wide stopband and insertion loss lower than 0.18 dB in the passband region. The rejection level is less than -20 dB from 2.98 up to 21.3 GHz. The filter size is 10.5 mm×12.7 mm, or 0.131 λg× 0.158 λg, where λg is the guided wavelength. The measured and simulated results of the filter is in good agreement with each other, which show the merits of low insertion loss and wide stopband.
Validation study of path loss models onijngnjournal
The radio wave propagation in form of path loss model plays very significant role in planning of any
wireless communication network. Measurement of signal strength of OFDM driven WiMAX technology at
2.6 GHz band is taken in Suburban Town of India. The results are analyzed and compared with Empirical
path loss models such as Hata-Okumura, Modified Hata and COST-231Hata. COST-231 model shows
highest path loss for suburban environment. These analyzed results establish that COST-231 model is
suitable for suburban environment also. Threshold RSSI estimates cell coverage probability in the area.
In this paper, variations in the capacitive fed suspended RMSA configurations have been proposed. Initially, the reference antenna consists of rectangular patch of size of (35.5 X 45.6) mm2 and a small rectangular feed patch of size of (1.4 X 4) mm2 residing on the same substrate suspended above the ground plane. Coaxial probe is used to feed the small patch which in turn excites the radiator patch electromagnetically, yielding a large impedance bandwidth (BW) of 39%, with good gain and broadside radiation pattern. By, meandering the ground plane of reference antenna with three rectangular slots, the prototype antenna is fabricated and measurement has been carried out to validate the result for compact broadband response. Later, by loading a pair of rectangular slots in the radiating patch of the reference antenna in addition to the rectangular slots in the ground plane, the prototype antenna is fabricated and measurement has been carried out to validate the result for compact dual band response.
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.
A Compact Reconfigurable Dual Band-notched Ultra-wideband Antenna using Varac...TELKOMNIKA JOURNAL
In this paper, a reconfigurable dual band-notched ultra-wideband (UWB) antenna is presented.
The antenna design consists of a circular shape with two pairs of the L-resonator. To realize the notch
characteristics in WLAN at 5.2 GHz and 5.8 GHz bands, the half wavelength of the L-resonator is
introduced in the design. The T-shaped notch is etched in the ground to enhance the bandwidth which
covers the UWB operating frequency range from 3.219–10.863 GHz. The proposed reconfigurable dual
band-notched UWB antenna shows good impedance matching for the simulated in the physical layout.
Furthermore, the proposed antenna has a compact size of 37.6x28 mm2. This proposed reconfigurable
design can provide an alternative solution for the wireless system in the designing of a band-notched
antenna with a good tuning capability.
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.
Improved Vivaldi Antenna with Radiation Pattern Control FeaturesTELKOMNIKA JOURNAL
Vivaldi antenna has been considered as a mitigation to the scattering effect of an antenna.
However, the current performance of Vivaldi antenna suffers from multipath effect, interfering signals and
radiation pattern control. This paper proposed an improved Vivaldi antenna which combined triple radiating
slot to enable control of radiation pattern features. This is accomplished by controlling the position of the
radiating element through the asymmetric arrangement of ideal switches to steer the beam in three
desired-directions. The Using operating frequency lied between 900 MHz and 2.5GHz, the proposed
design was fabricated and tested. Depending on the radiating element, the proposed anten na covered
about ±90º with an almost equal gain at the three different focal in contrast to ±45º coverage of traditional
rectangular microstrip antenna beam. The results satisfied pattern reconfigurability and the proposed
design can be very useful for wireless communications where multipath fading problems are frequently
encountered.
Inverted Diamond-shaped Notched Substrate and Patch for High-frequency Interf...IJECEIAES
Notches loaded on a patch antenna can affect significantly on the antenna impedance matching. Therefore, notching technique is an efficient way to reduce the electromagnetic interference with unwanted bands. In this paper, a novel inverted diamond - shaped closed-end slot on a substrate and vertexfed printed hexagonal patch ultra - wideband antenna is proposed for highfrequency band rejection. This antenna is fed using coplanar waveguide, and it is optimised by veering several patch parameters which further improved the inter bandwidth at both the lower and upper bands. However, the centrenotched band is shifted from 6GHz to 7.5GHz by cutting the inverted diamond shape in a special process. The developed ultra-wideband antenna is verified by comparing the simulation results with the measurement results. The measured results with a fractional bandwidth of 133% have a good agreement with the simulation results 146%. Moreover, the measured radiation showed omnidirectional patterns.
Bi-directional Beams Waveguide Slotted Antenna at Millimeter WaveTELKOMNIKA JOURNAL
This paper focused on designing a bi-directional beams waveguide slotted antenna at millimetre
wave spectrum. Waveguide slotted antenna is known for its highly directional pattern. By having bidirectional
pattern, the capacity of system coverage can be expanded. The design is implemented by using
antenna slot theory on a waveguide structure. The slotted are made on two wall surfaces and the
performance is compared to the slotted on single wall. The two models designs are simulated using
Computer Simulation Technology (CST) microwave software. The simulation results show that both
models operate at 30 GHz with minimum reflection coefficient of -24.63 and -25.01 dB respectively. The
two models achieved a fair high gain at 15.5 dB and 13.3 dB with directional beamwidth of 8.9 degree.
The proposed bi-directional beams structure achieved a comparable gain in both directions when
compared to the single direction.
A Compact Dual Band Dielectric Resonator Antenna For Wireless ApplicationsIJCNCJournal
This paper presents the design of a dual band rectangular Dielectric Resonator Antenna (DRA)
coupled to narrow slot aperture that is fed by microstrip line. The fundamental TE111 mode and
higher-order TE113 mode are excited with their resonant frequencies respectively. These
frequencies can be controlled by changing the DRA dimensions. A dielectric resonator with high
permittivity is used to miniaturize the global structure. The proposed antenna is designed to have
dual band operation suitable for both DCS (1710 - 1880 MHz) and WLAN (2400 - 2484 MHz)
applications. The return loss, radiation pattern and gain of the proposed antenna are evaluated.
Reasonable agreement between simulation and experimental results is obtained.
Impact of Using Modified Open Area Okumura-Hata Propagation Model in Determin...IJMERJOURNAL
ABSTRACT: This paper examines the applicability of the Okumura - Hata model in Malaysia in GSM frequency band. The study was carried out in the open area only since measurements provided from Malaysia Mobile were about the open areas. The mean square error (MSE) was calculated between measured path loss values and those predicted on basis of Okumura-Hata model for an open area. The MSE is up to 6dB, which is an acceptable value for the signal prediction. Therefore, the model gave a significant difference in an open area that allowed necessary changes to be introduced in the model. That error was minimized by subtracting the calculated MSE (15.31dB) from the original equation of open area for Okumura-Hata model. Modified equation was also verified for another cell in an open area in Malaysia and gave acceptable results.
A design of triple band slot loaded circular microstrip antenna for c- and x-...eSAT 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
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.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
In this paper, a low pass filter based on T-Shaped resonator is presented. The T-Shaped resonator consists of meandered lines and rectangular patches. Also, the LC model and transfer function of the proposed resonator is presented. For suppression of spurious harmonics, a bandstop structure consists of hexangular patches and open stubs has been utilized. Finally, the wide stopband microstrip lowpass filter with cutoff frequency 2.72 GHz has been simulated, fabricated and measured. The LPF has good characteristics such as wide stopband and insertion loss lower than 0.18 dB in the passband region. The rejection level is less than -20 dB from 2.98 up to 21.3 GHz. The filter size is 10.5 mm×12.7 mm, or 0.131 λg× 0.158 λg, where λg is the guided wavelength. The measured and simulated results of the filter is in good agreement with each other, which show the merits of low insertion loss and wide stopband.
Validation study of path loss models onijngnjournal
The radio wave propagation in form of path loss model plays very significant role in planning of any
wireless communication network. Measurement of signal strength of OFDM driven WiMAX technology at
2.6 GHz band is taken in Suburban Town of India. The results are analyzed and compared with Empirical
path loss models such as Hata-Okumura, Modified Hata and COST-231Hata. COST-231 model shows
highest path loss for suburban environment. These analyzed results establish that COST-231 model is
suitable for suburban environment also. Threshold RSSI estimates cell coverage probability in the area.
In this paper, variations in the capacitive fed suspended RMSA configurations have been proposed. Initially, the reference antenna consists of rectangular patch of size of (35.5 X 45.6) mm2 and a small rectangular feed patch of size of (1.4 X 4) mm2 residing on the same substrate suspended above the ground plane. Coaxial probe is used to feed the small patch which in turn excites the radiator patch electromagnetically, yielding a large impedance bandwidth (BW) of 39%, with good gain and broadside radiation pattern. By, meandering the ground plane of reference antenna with three rectangular slots, the prototype antenna is fabricated and measurement has been carried out to validate the result for compact broadband response. Later, by loading a pair of rectangular slots in the radiating patch of the reference antenna in addition to the rectangular slots in the ground plane, the prototype antenna is fabricated and measurement has been carried out to validate the result for compact dual band response.
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.
A Compact Reconfigurable Dual Band-notched Ultra-wideband Antenna using Varac...TELKOMNIKA JOURNAL
In this paper, a reconfigurable dual band-notched ultra-wideband (UWB) antenna is presented.
The antenna design consists of a circular shape with two pairs of the L-resonator. To realize the notch
characteristics in WLAN at 5.2 GHz and 5.8 GHz bands, the half wavelength of the L-resonator is
introduced in the design. The T-shaped notch is etched in the ground to enhance the bandwidth which
covers the UWB operating frequency range from 3.219–10.863 GHz. The proposed reconfigurable dual
band-notched UWB antenna shows good impedance matching for the simulated in the physical layout.
Furthermore, the proposed antenna has a compact size of 37.6x28 mm2. This proposed reconfigurable
design can provide an alternative solution for the wireless system in the designing of a band-notched
antenna with a good tuning capability.
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.
Improved Vivaldi Antenna with Radiation Pattern Control FeaturesTELKOMNIKA JOURNAL
Vivaldi antenna has been considered as a mitigation to the scattering effect of an antenna.
However, the current performance of Vivaldi antenna suffers from multipath effect, interfering signals and
radiation pattern control. This paper proposed an improved Vivaldi antenna which combined triple radiating
slot to enable control of radiation pattern features. This is accomplished by controlling the position of the
radiating element through the asymmetric arrangement of ideal switches to steer the beam in three
desired-directions. The Using operating frequency lied between 900 MHz and 2.5GHz, the proposed
design was fabricated and tested. Depending on the radiating element, the proposed anten na covered
about ±90º with an almost equal gain at the three different focal in contrast to ±45º coverage of traditional
rectangular microstrip antenna beam. The results satisfied pattern reconfigurability and the proposed
design can be very useful for wireless communications where multipath fading problems are frequently
encountered.
Inverted Diamond-shaped Notched Substrate and Patch for High-frequency Interf...IJECEIAES
Notches loaded on a patch antenna can affect significantly on the antenna impedance matching. Therefore, notching technique is an efficient way to reduce the electromagnetic interference with unwanted bands. In this paper, a novel inverted diamond - shaped closed-end slot on a substrate and vertexfed printed hexagonal patch ultra - wideband antenna is proposed for highfrequency band rejection. This antenna is fed using coplanar waveguide, and it is optimised by veering several patch parameters which further improved the inter bandwidth at both the lower and upper bands. However, the centrenotched band is shifted from 6GHz to 7.5GHz by cutting the inverted diamond shape in a special process. The developed ultra-wideband antenna is verified by comparing the simulation results with the measurement results. The measured results with a fractional bandwidth of 133% have a good agreement with the simulation results 146%. Moreover, the measured radiation showed omnidirectional patterns.
Bi-directional Beams Waveguide Slotted Antenna at Millimeter WaveTELKOMNIKA JOURNAL
This paper focused on designing a bi-directional beams waveguide slotted antenna at millimetre
wave spectrum. Waveguide slotted antenna is known for its highly directional pattern. By having bidirectional
pattern, the capacity of system coverage can be expanded. The design is implemented by using
antenna slot theory on a waveguide structure. The slotted are made on two wall surfaces and the
performance is compared to the slotted on single wall. The two models designs are simulated using
Computer Simulation Technology (CST) microwave software. The simulation results show that both
models operate at 30 GHz with minimum reflection coefficient of -24.63 and -25.01 dB respectively. The
two models achieved a fair high gain at 15.5 dB and 13.3 dB with directional beamwidth of 8.9 degree.
The proposed bi-directional beams structure achieved a comparable gain in both directions when
compared to the single direction.
A Compact Dual Band Dielectric Resonator Antenna For Wireless ApplicationsIJCNCJournal
This paper presents the design of a dual band rectangular Dielectric Resonator Antenna (DRA)
coupled to narrow slot aperture that is fed by microstrip line. The fundamental TE111 mode and
higher-order TE113 mode are excited with their resonant frequencies respectively. These
frequencies can be controlled by changing the DRA dimensions. A dielectric resonator with high
permittivity is used to miniaturize the global structure. The proposed antenna is designed to have
dual band operation suitable for both DCS (1710 - 1880 MHz) and WLAN (2400 - 2484 MHz)
applications. The return loss, radiation pattern and gain of the proposed antenna are evaluated.
Reasonable agreement between simulation and experimental results is obtained.
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.
BODY ANTENNA WITH DGS FOR BODY CENTRIC WIRELESS COMMUNICATION SYSTEMjantjournal
This paper presents modified patch antenna for 3 GHz and 5 GHz operating frequencies. Here different approaches are studied by varying slot sizes, defected ground size, notch and also changing feed position. Insertion of slots gives dual frequency operation. Notch provides shifting of lower frequency band towards left hand side. Here combined effect of each techniques adopted gives desired result. Proposed antenna resonates for 3 and 5 GHz frequency. Simulation is done using IE3D software for various parameters. Return loss of final design was -12.17 dB for 3 GHz frequency and VSWR of 1.65. For 5 GHz simulation response was -10.04dB return loss and VSWR of 1.91. Proposed antenna is fabricated giving different details. Paper gives good agreement between measured and simulated results.
BODY ANTENNA WITH DGS FOR BODY CENTRIC WIRELESS COMMUNICATION SYSTEMjantjournal
This paper presents modified patch antenna for 3 GHz and 5 GHz operating frequencies. Here different approaches are studied by varying slot sizes, defected ground size, notch and also changing feed position. Insertion of slots gives dual frequency operation. Notch provides shifting of lower frequency band towards left hand side. Here combined effect of each techniques adopted gives desired result. Proposed antenna resonates for 3 and 5 GHz frequency. Simulation is done using IE3D software for various parameters. Return loss of final design was -12.17 dB for 3 GHz frequency and VSWR of 1.65. For 5 GHz simulation response was -10.04dB return loss and VSWR of 1.91. Proposed antenna is fabricated giving different details. Paper gives good agreement between measured and simulated results.
BODY ANTENNA WITH DGS FOR BODY CENTRIC WIRELESS COMMUNICATION SYSTEMjantjournal
This paper presents modified patch antenna for 3 GHz and 5 GHz operating frequencies. Here different approaches are studied by varying slot sizes, defected ground size, notch and also changing feed position. Insertion of slots gives dual frequency operation. Notch provides shifting of lower frequency band towards left hand side. Here combined effect of each techniques adopted gives desired result. Proposed antenna resonates for 3 and 5 GHz frequency. Simulation is done using IE3D software for various parameters. Return loss of final design was -12.17 dB for 3 GHz frequency and VSWR of 1.65. For 5 GHz simulation response was -10.04dB return loss and VSWR of 1.91. Proposed antenna is fabricated giving different details. Paper gives good agreement between measured and simulated results.
Gain enhancement of dielectric resonator antenna for millimeter wave applicat...TELKOMNIKA JOURNAL
In this paper, dielectric resonator antenna (DRA) with enhanced gain operating on the higher
order mode (푇퐸훿15
푥 ) is presented. The dielectric resonator antenna with dielectric constant 휀푟 of 10 and
loss tangent of 0.002 is used. The DRA is fed by microstrip line through an aperture slot. The proposed
antenna is designed at 26 GHz and achieved a gain of 7.9 dBi with corresponding simulated radiation
efficiency of 93%. The impedance bandwidth of 1.5 GHz from 25.1 GHz to 26.6 GHz has been achieved.
The reflection coefficient, antenna gain, radiation patterns, and efficiency of the antenna are studied.
Simulations are performed using CST microwave studio, and their results are presented.
Two-section branch-line hybrid couplers based broadband transmit/receive switchIJECEIAES
This article introduces a broadband microstripline-based transmit/receive switch for 7-Tesla magnetic resonance imaging. The designed switch aims to handle a signal of multiple frequencies to/from a multi-tuned radio-frequency coil that resonates at frequencies corresponding to the speed of precession of a wide range of atomic X-nuclei, at the same time and without tuning. These include 1H, 23Na, 13C, 31P, 19F, and 7Li used in magnetic resonance spectroscopy as a measure to the existence of many diseases. The fundamental and third harmonic center frequencies of the switch are adjusted to resonate at two broadbands covering a wide range of atomic X-nuclei. Two section branch-line hybrid couplers with phase inverters are designed to build the broadband switch. The designed switch used the minimum trace widths of transmission lines that reveal a compact size without increasing the heat and then the loss beyond specific values. The couplers and the switch S-parameters exhibited good return loss (<-10 dB), high isolation (<-40 dB), less insertion loss (<1 dB) and two clear wide bands covering many atomic X-nuclei used in diagnosis, at the same time and without the need for any tuning circuit during operation.
BODY ANTENNA WITH DGS FOR BODY CENTRIC WIRELESS COMMUNICATION SYSTEMjantjournal
This paper presents modified patch antenna for 3 GHz and 5 GHz operating frequencies. Here different approaches are studied by varying slot sizes, defected ground size, notch and also changing feed position. Insertion of slots gives dual frequency operation. Notch provides shifting of lower frequency band towards left hand side. Here combined effect of each techniques adopted gives desired result. Proposed antenna resonates for 3 and 5 GHz frequency. Simulation is done using IE3D software for various parameters. Return loss of final design was -12.17 dB for 3 GHz frequency and VSWR of 1.65. For 5 GHz simulation response was -10.04dB return loss and VSWR of 1.91. Proposed antenna is fabricated giving different details. Paper gives good agreement between measured and simulated results.
BODY ANTENNA WITH DGS FOR BODY CENTRIC WIRELESS COMMUNICATION SYSTEMjantjournal
This paper presents modified patch antenna for 3 GHz and 5 GHz operating frequencies. Here different approaches are studied by varying slot sizes, defected ground size, notch and also changing feed position. Insertion of slots gives dual frequency operation. Notch provides shifting of lower frequency band towards left hand side. Here combined effect of each techniques adopted gives desired result. Proposed antenna resonates for 3 and 5 GHz frequency. Simulation is done using IE3D software for various parameters. Return loss of final design was -12.17 dB for 3 GHz frequency and VSWR of 1.65. For 5 GHz simulation response was -10.04dB return loss and VSWR of 1.91. Proposed antenna is fabricated giving different details. Paper gives good agreement between measured and simulated results.
BODY ANTENNA WITH DGS FOR BODY CENTRIC WIRELESS COMMUNICATION SYSTEMjantjournal
This paper presents modified patch antenna for 3 GHz and 5 GHz operating frequencies. Here different approaches are studied by varying slot sizes, defected ground size, notch and also changing feed position. Insertion of slots gives dual frequency operation. Notch provides shifting of lower frequency band towards left hand side. Here combined effect of each techniques adopted gives desired result. Proposed antenna resonates for 3 and 5 GHz frequency. Simulation is done using IE3D software for various parameters. Return loss of final design was -12.17 dB for 3 GHz frequency and VSWR of 1.65. For 5 GHz simulation response was -10.04dB return loss and VSWR of 1.91. Proposed antenna is fabricated giving different details. Paper gives good agreement between measured and simulated results.
BODY ANTENNA WITH DGS FOR BODY CENTRIC WIRELESS COMMUNICATION SYSTEMjantjournal
This paper presents modified patch antenna for 3 GHz and 5 GHz operating frequencies. Here different approaches are studied by varying slot sizes, defected ground size, notch and also changing feed position. Insertion of slots gives dual frequency operation. Notch provides shifting of lower frequency band towards left hand side. Here combined effect of each techniques adopted gives desired result. Proposed antenna resonates for 3 and 5 GHz frequency. Simulation is done using IE3D software for various parameters. Return loss of final design was -12.17 dB for 3 GHz frequency and VSWR of 1.65. For 5 GHz simulation response was -10.04dB return loss and VSWR of 1.91. Proposed antenna is fabricated giving different details. Paper gives good agreement between measured and simulated results.
BODY ANTENNA WITH DGS FOR BODY CENTRIC WIRELESS COMMUNICATION SYSTEMjantjournal
This paper presents modified patch antenna for 3 GHz and 5 GHz operating frequencies. Here different approaches are studied by varying slot sizes, defected ground size, notch and also changing feed position. Insertion of slots gives dual frequency operation. Notch provides shifting of lower frequency band towards left hand side. Here combined effect of each techniques adopted gives desired result. Proposed antenna resonates for 3 and 5 GHz frequency. Simulation is done using IE3D software for various parameters. Return loss of final design was -12.17 dB for 3 GHz frequency and VSWR of 1.65. For 5 GHz simulation response was -10.04dB return loss and VSWR of 1.91. Proposed antenna is fabricated giving different details. Paper gives good agreement between measured and simulated results.
BODY ANTENNA WITH DGS FOR BODY CENTRIC WIRELESS COMMUNICATION SYSTEMjantjournal
This paper presents modified patch antenna for 3 GHz and 5 GHz operating frequencies. Here different approaches are studied by varying slot sizes, defected ground size, notch and also changing feed position. Insertion of slots gives dual frequency operation. Notch provides shifting of lower frequency band towards left hand side. Here combined effect of each techniques adopted gives desired result. Proposed antenna
resonates for 3 and 5 GHz frequency. Simulation is done using IE3D software for various parameters. Return loss of final design was -12.17 dB for 3 GHz frequency and VSWR of 1.65. For 5 GHz simulation response was -10.04dB return loss and VSWR of 1.91. Proposed antenna is fabricated giving different
details. Paper gives good agreement between measured and simulated results.
BODY ANTENNA WITH DGS FOR BODY CENTRIC WIRELESS COMMUNICATION SYSTEMjantjournal
This paper presents modified patch antenna for 3 GHz and 5 GHz operating frequencies. Here different approaches are studied by varying slot sizes, defected ground size, notch and also changing feed position. Insertion of slots gives dual frequency operation. Notch provides shifting of lower frequency band towards left hand side. Here combined effect of each techniques adopted gives desired result. Proposed antenna resonates for 3 and 5 GHz frequency. Simulation is done using IE3D software for various parameters. Return loss of final design was -12.17 dB for 3 GHz frequency and VSWR of 1.65. For 5 GHz simulation response was -10.04dB return loss and VSWR of 1.91. Proposed antenna is fabricated giving different
details. Paper gives good agreement between measured and simulated results.
BODY ANTENNA WITH DGS FOR BODY CENTRIC WIRELESS COMMUNICATION SYSTEMjantjournal
This paper presents modified patch antenna for 3 GHz and 5 GHz operating frequencies. Here different approaches are studied by varying slot sizes, defected ground size, notch and also changing feed position. Insertion of slots gives dual frequency operation. Notch provides shifting of lower frequency band towards left hand side. Here combined effect of each techniques adopted gives desired result. Proposed antenna
resonates for 3 and 5 GHz frequency. Simulation is done using IE3D software for various parameters. Return loss of final design was -12.17 dB for 3 GHz frequency and VSWR of 1.65. For 5 GHz simulation response was -10.04dB return loss and VSWR of 1.91. Proposed antenna is fabricated giving different
details. Paper gives good agreement between measured and simulated results.
Similar to Design and simulation of broadband rectangular microstrip antenna (20)
IoT traffic management and integration in the QoS supported networkBASIM AL-SHAMMARI
This paper proposes: 1) a traffic flow management
policy, which allocates and organizes machine type communication
(MTC) traffic flows network resources sharing within evolved
packet system (EPS); 2) an access element as a wireless sensor
network gateway for providing an overlaying access channel
between the machine type devices and EPS; and 3) it addresses
the effect and interaction in the heterogeneity of applications,
services and terminal devices, and the related quality of service
(QoS) issues among them. This paper overcomes the problems
of network resource starvation by preventing deterioration of
network performance. The scheme is validated through simulation,
which indicates the proposed traffic flow management policy
outperforms the current traffic management policy. Specifically,
simulation results show that the proposed model achieves an
enhancement in QoS performance for the MTC traffic flows,
including a decrease of 99.45% in packet loss rate (PLR), a
decrease of 99.89% in packet end to end (E2E) delay, a decrease
of 99.21% in packet delay variation (PDV). Furthermore, it
retains the perceived quality of experience of the real time application
users within high satisfaction levels, such as the voice
over long term evolution service possessing a mean opinion
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service within the standardized values of a 3GPP body,
with a decrease of 85.28% in PLR, a decrease of 85% in packet
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Index Terms—Application quality of service (AQoS), end to
end (E2E) delay, gateway, human type communication (HTC),
Internet of Things (IoT), jitter, machine type communication
(MTC), network QoS (NQoS), quality of experience (QoE), QoS
class identifier (QCI), traffic policy.
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In this work, many techniques are suggested and analyses for
rectangular microstrip antenna (RMSA) operating in X-band for 10 GHz
center frequency. These approaches are: lowering quality factor, shifting
feeding point , using reactive loading and modification of the patch shape.
The design of a RMSA is made to several dielectric materials, and the
selection is based upon which material gives a better antenna performance
with reduced surface wave loss. Duroid 5880 and Quartz are the best materials
for proposed design to achieve a broader Bandwidth (BW) and better
mechanical characteristics than using air. The overall antenna BW for RMSA
is increased by 11.6 % with Duroid 5880 with shifted feeding point and with
central shorting pin (Reactive loading) while that for Quartz is 17.4 %.
Modification of patch shape with similar improving techniques gives an
overall increasing VSWR bandwidth of 26.2 % for Duroid 5880 and a
bandwidth of 30.9 % for Quartz. These results are simulated using Microwave
Office package version 3.22, 2000.
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GHz exhibits circularly polarized far-field radiation pattern. The proposed antennas have been
simulated and analyzed using method of moments (MoM) based software package Microwave
Office 2009 v9.0. The results show that the antenna has dual-band frequency operation by using slit
load.
Circularly polarized microstrip antenna with reactive load design for wireles...BASIM AL-SHAMMARI
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The proposed antennas have been simulated and analyzed using method of moments (MoM) based software package Microwave Office 2008 v8.0. The results show that the bandwidth of the antenna increases by using reactive load. The simulated gain of the antenna is over 6 dB.
Dual band microstrip antenna with slit load design for wireless local area ne...BASIM AL-SHAMMARI
This paper presents a design of dual frequency band operation nearly square patch antenna
for IEEE 802.11b,g (2.4Ghz-2.4835GHz) and IEEE 802.11a (5.15GHz-5.25GHz)by using a patch
antenna. The patch and ground plane are separated by a substrate; the radiating patch have two pairs
of orthogonal slits cut from the edge, this antenna has wide bandwidth in the frequency band of
(WLAN) and with a return loss ≤ −10 dB from 2.4 GHz to 2.48 GHz and from 5.12 GHz to 5.32
GHz exhibits circularly polarized far field radiation pattern. The proposed antennas have been
simulated and analyzed using method of moments (MoM) based software package Microwave
Office 2009 v9.0. The results show that the antenna has dual band frequency operation by using slit
load.
Circularly polarized microstrip antenna with reactive load design for wireles...BASIM AL-SHAMMARI
Abstract
This paper presents a design of microstrip antenna for IEEE 802.11b and for IEEE 802.11g using a nearly square patch antenna, excited by a standard miniature adapter probe feed line. The patch and ground plain are separated by a substrate; the radiating patch is loaded by a central shorting pin and feeding probe loaded by a series capacitor. This antenna has wide bandwidth in the frequency band of (WLAN) and with a return loss ≤ −10 dB from 2.4 GHz to 2.48 GHz exhibits circularly polarized far field radiation pattern.
The proposed antennas have been simulated and analyzed using method of moments (MoM) based software package Microwave Office 2008 v8.0. The results show that the bandwidth of the antenna increases by using reactive load. The simulated gain of the antenna is over 6 dB.
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Length: 30 minutes
Session Overview
-------------------------------------------
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Design and simulation of broadband rectangular microstrip antenna
1. Eng.Tech.V0l.26,No1,2008
93
Design and Simulation of Broadband Rectangular
Microstrip Antenna
Adil Hameed Ahmad and Basim Khalaf Jar’alla
Received on:5 / 5/2005
Accepted on:5 / 3/ 2006
Abstract
In this work, many techniques are suggested and analyses for
rectangular microstrip antenna (RMSA) operating in X-band for 10 GHz
center frequency. These approaches are: lowering quality factor, shifting
feeding point , using reactive loading and modification of the patch shape.
The design of a RMSA is made to several dielectric materials, and the
selection is based upon which material gives a better antenna performance
with reduced surface wave loss. Duroid 5880 and Quartz are the best materials
for proposed design to achieve a broader Bandwidth (BW) and better
mechanical characteristics than using air. The overall antenna BW for RMSA
is increased by 11.6 % with Duroid 5880 with shifted feeding point and with
central shorting pin (Reactive loading) while that for Quartz is 17.4 %.
Modification of patch shape with similar improving techniques gives an
overall increasing VSWR bandwidth of 26.2 % for Duroid 5880 and a
bandwidth of 30.9 % for Quartz. These results are simulated using Microwave
Office package version 3.22, 2000.
اﻟﺨﻼﺻﺔ
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ﻏﻴﺭﺍﻟﻟﻠﻬﻭﺍﺌﻲ ﺍﻟﺸﻜل ﺘﻌﺩﻴل ﻭ ﻔﻌﺎل.
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ﻋﺎﺯﻟﺔ ﻤﻭﺍﺩ,ﺘﻘ ﻤﻊ ﻟﻠﻬﻭﺍﺌﻲ ﺍﺩﺍﺀ ﺍﻓﻀل ﺍﻋﻁﻰ ﺍﻟﺫﻱ ﺍﻟﺘﺼﻤﻴﻡ ﺍﺨﺘﻴﺎﺭ ﺘﻡ ﻗﺩ ﻭﺍﻟﺨﺴﺎﺌﺭ ﻨﺴﺒﺔ ﻠﻴل
ﺍﻟﺴﻁﺤﻴﺔ ﺍﻟﻤﻭﺠﺔ ﺘﻭﻟﻴﺩ ﺘﺎﺜﻴﺭ ﺒﺴﺒﺏ,ﺍل ﻫﻤﺎ ﺍﻟﻤﻌﺘﻤﺩ ﻟﻠﺘﺼﻤﻴﻡ ﻤﺎﺩﺘﻴﻥ ﺍﻓﻀل ﻜﺎﻨﺕ)Quartz(ﻭ
ﺍل)Duroid5880(,ﻋﻤ ﺤﺯﻤﺔ ﺍﻭﺴﻊ ﺍﻋﻁﺕ ﺍﻟﻤﺎﺩﺘﻴﻥ ﻫﺎﺘﻴﻥ ﺍﻥ ﺤﻴﺙﺘﺭﺩﺩﻱ لﺍﻟﻤﻭﺍﺩ ﻤﻥ
ﺍﻻﺨﺭﻯﺒ ﺍﻓﻀل ﻭﻜﺫﻟﻙﺨﻭﺍﺼﻬﺎﺍﻟﻤﻴﻜﺎﻨﻴﻜﻴﺔ.
ﺍﻋﻁى ﻟﻘﺩﺍ ﺫﻭ ﺍﻟﺩﻗﻴﻕ ﺍﻟﺸﺭﻴﻁﻲ ﺎﻟﻬﻭﺍﺌﻲﺍﻟﻤﺴﺘﻁﻴل ﻟﺸﻜلﺍل ﻤﺎﺩﺓ ﻤﻊ)Duroid5880(
ﺯﻴﺎﺩﺓﺘﺭﺩﺩﻱ ﺍﺸﺘﻐﺎل ﺤﺯﻤﺔ ﻋﺭﺽﻜﻠﻲﺒﻤﻘﺩﺍﺭ)11.6 %(,ﺍﻤﺎﺘﻠﻙﺍل ﻤﺎﺩﺓ ﻤﻊ)Quartz(ﻓﻘﺩ
ﺒ ﺍﻟﺯﻴﺎﺩﺓ ﻜﺎﻨﺕﻌﺭﺽﺍﻷﺸﺘﻐﺎل ﺤﺯﻤﺔﺒﻤﻘﺩﺍﺭ( 17.4 %).ﻟﻠﺸﺭﻴﺤﺔ ﺍﻟﺸﻜل ﺘﻌﺩﻴل ﺘﻘﻨﻴﺔ ﺍﻤﺎ
ﻟﻬﻭﺍﺌﻲ ﺍﻟﺩﻗﻴﻘﺔ)Duroid5880(ﺍﻋﻁﻰ ﻗﺩﺯﻴﺎﺩﺓﺒﻤ ﺤﺯﻤﺔ ﻋﺭﺽﻘﺩﺍﺭ)26.2 %(ﻭ)30.9
%(ﻟﻬﻭﺍﺌﻲQuartz)(.
ﺘﻡﺍﺴﺘﺨﺩﺍﻡﺒﺭﻨﺎﻤﺞﺍﻟﻤﺤﺎﻜﺎﺓ)(Microwave Office Package ver. 3.22, 2000
ﺍﻟﻨﺘﺎﺌﺞ ﻟﻤﺤﺎﻜﺎﺕ.
2. Eng.Tech.V0l.26,No1,2008
93
1. Introduction
The arrangement of an arbitrary
shaped patch microstrip antenna is
given in Figure 1. It consists of patch,
substrate, ground plane and feeding
point. A patch is a two-dimensional
antenna element, which is often
rectangular in shape. It is of a very
thin thickness (t) of metallic strip on
top of a material known as the
substrate with thickness h (h«λo,
usually 0.003λo≤h≤0.05λo, where λo is
free space wavelength) above a
ground plane[1].The microstrip
antenna (MSA) can be excited
directly either by a coaxial probe or
by a microstrip line. It can also be
excited indirectly using
electromagnetic coupling or aperture
coupling and a coplanar waveguide
feed, in which case there is no direct
metallic contact between the feed line
and the patch. The microstrip patch is
designed so that its pattern has
maximum normal to the patch plane
(broadside radiator) by choosing a
certain field configuration mode. For
rectangular patch, the length L of the
element is usually λo/3<L<λo/2. The
strip (patch) and the ground plane are
separated by a dielectric (substrate).
Microstrip antennas have a very
high antenna quality factor (Q). This
factor represents the losses associated
with the antenna and a large quality
factor leads to narrow bandwidth and
low efficiency. Quality factor can be
reduced by increasing the thickness of
the dielectric substrate. But as the
thickness increases, an increasing
fraction of the total power delivered
by the source goes into a surface
wave. This surface wave contribution
can be counted as an unwanted power
loss since it is ultimately scattered at
the dielectric bends and causes
degradation of the antenna
characteristics. However, surface
waves can be minimized by the use of
photonic bandgap structures [2].
Other problems such as lower gain
and lower power handling capacity
can be overcome by using an array
configuration for the elements. The
patch is generally square, rectangular,
circular, triangular, and elliptical or
some other common shapes .
Microstrip antennas have narrow
bandwidth, typically 1-5%, which is
the major limiting factor for the
widespread application of these
antennas. Increasing the bandwidth of
MSA has been the major thrust of
researches in this field [3,4 ].
2. Analyses and Modeling of
RMSA
Three methods of analysis are
commonly used to calculate
microstrip antenna (MSA) parameters
[5,6]. These are:Transmission line
model, cavity model, and full wave
analysis.
It is useful to model the microstrip
antenna as a transmission line . This
model is the simplest of all and it
gives good physical insight but it is
less accurate. It represents the MSA by
two slots of width W and height h,
separated by a transmission line of
length L. The microstrip is essentially
a non homogeneous line of two
dielectrics, typically the substrate and
air. An effective dielectric constant
(εreff) must be obtained in order to
account for the fringing and the wave
propagation in the line. The
expression for εreff is given by [1]:
2
1
121
2
1
2
1
−
⎥
⎦
⎤
⎢
⎣
⎡
+
−
+
+
=
W
hrr
reff
εε
ε
……
(1)
3. 2
Fig. 2 shows a RMSA of length L,
width W resting on a substrate of
height h. The co-ordinate axis is
selected such that the length is along
the y direction, width is along the x
direction .
In order to operate in the
fundamental TM10 mode, the length of
the patch must be slightly less than λ/2
where λ is the wavelength in the
dielectric medium and is equal to
λo/√εreff where λo is the free space
wavelength.
In Fig. 2a, the MSA is represented
by two slots, separated by a
transmission line of length L and open
circuited at both ends. Along the
width of the patch, the voltage is max
and current is minimum due to the
open ends. The fields at the edges can
be resolved into normal and tangential
components with respect to the
ground plane as in Fig.2b.
The dimensions of the patch along
its length have now been extended on
each end by a distance ∆L, which is
given empirically by [7]:
)8.0)(258.0(
)264.0)(3.0(
412.0
+−
++
=∆
h
W
h
W
L
reff
reff
ε
ε h
.
(2)
The effective length of the patch Leff
now becomes:
Leff = L+2∆L
…. (3)
For a given resonance frequency fo,
the effective length is given as:
reffo
eff
f
c
L
ε2
= …. (4)
Where c is the speed of light.
For a rectangular Microstrip patch
antenna, the resonance frequency for
any TMmn mode is given as:
2
1
22
2 ⎥
⎥
⎦
⎤
⎢
⎢
⎣
⎡
⎟
⎠
⎞
⎜
⎝
⎛
+⎟
⎠
⎞
⎜
⎝
⎛
=
W
n
L
mc
f
reff
o
ε
…. (5)
Where m and n are modes along L and
W respectively.
For efficient radiation, the width W is
given as [8] :
( )
2
1
2
+
=
r
of
c
W
ε
…. (6)
The cavity model is more accurate
and gives good physical insight but is
complex in nature. The full wave
models are extremely accurate,
versatile and can treat single elements,
finite and infinite arrays, stacked
elements, arbitrary shaped elements
and coupling .
The four most popular feed
techniques used in MSA are the
microstrip line, coaxial probe ,
aperture coupling and proximity
coupling [1, 7].
The input impedance should be
accurately known so that a good
match between the element and the
feed can be designed. Referring to
Fig. 3, the input impedance at the feed
point (xo ) is [1,9]:
)(cos
)cos(
1
)( 2
o
mr
oin x
nGG
xZ β
π+
=
Where Gr is the self conductance
given by the following three relations,
depending on
W/λo :
2
2
90 o
r
W
G
λ
= , for W<0.35λo
2
60
1
120 πλ
−=
o
r
W
G , for 0.35λo
≤ W ≤ 2 λo
4. 3
o
r
W
G
λ120
= , for 2 λo≤ W
and Gm is the mutual conductance
between the patch ends. At resonance
and Gr>>Gm then the input
impedance becomes:
⎟
⎠
⎞
⎜
⎝
⎛
== o
r
inoin x
LG
RxZ
π2
cos
1
)(
…. (7)
A microstrip antenna is basically a
broadside
radiator, which has a relatively large
beam width and low gain
characteristics. The formulas for the E
and H plane radiation patterns are
given by [10]:
E-plane:
F(Φ) = { sin[ (koh/2)cosΦ]
/(koh/2)cosΦ}.cos[ (koL/2)cosΦ]
…. (8)
H-plane:
F(θ) = { sin[ (kow/2)cosθ]
/(kow/2)cos θ }.sin θ
…. (9)
Where:
o
ok
λ
π2= (free space wave
number)
The half power beam widths in the
H and E planes are given by [ 11]:
__________
θ BH = 2 cos – 1
[ | 1 . . ]
√ ( 2 + ko W )
….. (10)
___________________
|
7.03______
θ BE = 2 cos – 1
[ √ ( 3 ko
2
Le
2
+
ko
2
h2
) ]
….. (11)
Thus beam width can be increased
by choosing a smaller element, thus
reducing W and L. For a given
resonant frequency these dimensions
may be changed, by selecting a
substrate having a higher relative
permittivity. As beam width increases,
element gain and directivity decrease,
however, efficiency is unaffected .
The expression for approximately
calculating the directivity D of the
rectangular microstrip antenna is
given by [10] :
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
++≅
r
WD
ε
6.1log106.62.0
dB
…….
(12)
For other geometries, the values of
equivalent W can be obtained by
equating its area with that of the
rectangular microstrip antenna [12].
The most serious limitation of the
microstrip antenna is its narrow BW.
The BW could be defined in terms of
its VSWR or input impedance
variation with frequency or in terms
of radiation parameters. For the
circularly polarized antenna, BW is
defined in terms of the Axial Ratio .
VSWR is a very popular parameter for
determining the BW of a particular
antenna configuration(1≤ VSWR ≤ 2 )
5. 4
as an acceptable interval for
determining the BW of the antenna.
BW is presented more concisely as a
percentage where:
%100% ×
∆
=
of
f
BW
…. (13)
Where ∆f is the width of the range of
acceptable frequencies, and fo is the
resonant frequency of the antenna
[10].
The expressions for approximately
calculating the percentage BW of the
(RMSA) antenna in terms of patch
dimensions and substrate parameters
is given by[13]:
%
L
WhA
BW
ro ελ
×
=
…. (14)
Where A is constant:
A = 180 for
045.0≤
ro
h
ελ
A = 200 for
075.0045.0 ≤≤
ro
h
ελ
A = 220 for
07.0≥
ro
h
ελ
With an increase in W, bandwidth
increases. However, W should be
taken less than λ to avoid excitation of
higher order modes.
The BW of the (MSA) can also
inversely proportional to its quality
factor Q and is given by [1].
BW=(VSWR-1)/(Q√VSWR) ….
(15)
The BW is usually specified as
frequency range over which VSWR ≤
2.
3. Design
considerations and
Process of Broadband
MSA
The methods for increasing
the BW of (MSA)'s are continuously
getting upgraded. The search for an
ideal broadband (MSA) is still
continuing. Perhaps a combination of
various approaches would lead to an
optimum broadband configuration
[3,5].
There are various techniques for
increasing the bandwidth BW of
(MSA)'s. The main techniques used to
increase the bandwidth are presented
briefly as[14]:
a) Low Quality Factor :
The principle of introducing low
quality factor of the cavity below the
patch can be achieved by:
. Low dielectric constant .
. Larger thickness of the substrate
but it is restricted by the surface wave
generation leading to low gain and
low efficiency of the antenna .
b) Modified Shape Patches :
The regular (MSA) configurations,
such as rectangular and circular
patches have been modified to
rectangular ring and circular ring,
respectively, to enhance the BW. The
larger BW is because of a reduction in
the quality factor of the patch
resonator, which is due to less energy
stored beneath the patch and higher
radiation. In this work the modified
shape is developed as a compact
model; it has nearly a trapezoidal
shape, its dimension consist of a
6. 5
combination from three rectangular
patches one at resonance (center
frequency of the operating band)
which gives the length of the patch
and the other two at beginning
frequency and end frequency of the
operating bandwidth which gives the
two widths of the trapezoidal
shape[12].
c) Multilayer Configurations :
In the multilayer configuration, two
or more patches on different layers of
the dielectric substrate are stacked on
each other. Based on the coupling
mechanism, these configurations are
categorized as electromagnetically
coupled or aperture-coupled
microstrip antennas [12].
The design process of broadband
MSA is based mainly on the
measurements acquired from the
narrowband rectangular antenna using
single layer configuration. The
antenna is assumed passive, linearly
polarized, fed by a coaxial probe with
input impedance nearly of 50 ohms.
The patch antenna element is
designed to radiate or operate with a
narrow impedance bandwidth.
The narrow bandwidth of the
microstrip antenna can be widened by
using combination between lowering
Q-factor, modified shaped patches,
and reactive loading approaches.
To achieve the broad banding of
the microstrip antenna, it is important
to determine the requirement arises
with such design. The requirements
needed to start the design process of a
broadband microstrip antenna are:
a- Type of substrate material to be
choosen.
b- The center frequency, and
c- The operating bandwidth.
The substrate material is important
in the successful design, where a low
quality factor of the cavity below the
patch can be achieved by proper
choice of the substrate material. The
center frequency of the antenna is 10
GHz designed to operate at whole X-
band .
The substrate height is limited by the
excitation of surface wave, and then
choice is based on Woods criterion
which depends on the operated
frequency and substrate material [7]:
h<0.07λo for εr≈ 2.3 , and h<0.023λo
for εr≈10
Assuming the antenna is operating to
cover the whole X-band range from 8
GHz to 12 GHz. For each frequency
there is a desired substrate height
associated with it. This height is based
on the above criterion. For f = 12
GHz then λo = 2.5 cm , the calculated
heights for both dielectrics are:
h = 0.07 λo = 0.175 cm for εr≈ 2.3,
and h = 0.023λo = 0.0575 cm for
εr≈10.
Therefore for εr≈ 2.3 the height
must be 0.175 cm or less, and for
εr≈10 the height must be 0.0575 cm or
less. For proper design, the choice is
made for εr≈ 2.3 is 0.17 cm and for
εr≈10 is 0.057 cm, since the antenna is
assumed to cover the X-band, i.e. to
stay in the safe side if antenna is
operating in the upper frequency limit
at 12 GHz.
The flow chart in Figure 4 explains
the design process. During phase 1 of
the work, the permittivity of the
substrate will be tested. This process
had to be carried out several times to
reach an optimal value of substrate
permittivity that gives a wider BW
using accurate permittivity values.
Phase one also oversaw the selection
of substrate heights to reduce surface
wave excitation. In phase two, three
narrowband patches were designed.
The first one was at the center
frequency of the band, the second was
at the beginning frequency of the band
7. 6
and the third one was at the end
frequency of the band. The patches
were thoroughly tested for bandwidth
and tuned to best match the input
impedance. Phase three involved in-
depth research regarding possible
broadband techniques. The best
scheme is chosen based on
manufacturing simplicity without
compromising performance over the
frequency band concerned. The
modified patch has nearly a
trapezoidal shape as shown in Fig. 5
with its new dimensions .
The feeding point is the same as that
point of the patch at the beginning
frequency of the band, with some
amount of offset to match Zin .
Central pin may improve the purity
of the resonant mode. An addition of a
shorting pin acts as an extra parameter
to control the mode excitation.
4. Design Examples
[15]
To achieve the requirements, two
design examples are considered for X-
band applications. The patch antenna
element is designed to operate at 10
GHz as center frequency, and to
widen the bandwidth as far as possible
to cover X-band. The calculations are
made step by step from dielectric
materials that have low dielectric
constant to higher one.
Example one: Rectangular patch
design, dielectric material RT Duroid
5880, dielectric constant εr=2.2, loss
tangent<0.0009, operating
frequency=10 GHz, λo=3 cm.
• The height (h) must be less
than 0.175 cm for εr≈ 2.3.
Then height should be
h=0.17 cm.
• The width of the MSA is
given by equation (6), where
W=1.1859 cm
• Eqn(1) gives the effective
dielectric constant as
εreff=1.9638
• Eqn (4) gives the effective
length as: Leff =1.0704 cm
• Eqn (2) gives the length
extension as: ∆L=0.0864 cm
The actual length is obtained
from eqn (3) as:
L = Leff -2∆L then
L=0.8976 cm
The ground plane dimensions are L
g=1.9176 cm and W g=2.2059 cm
Feed point location where the input
impedance is nearly 50 ohms is: Xf
= W /2 and Yf = L / (2√ εreff ) then
Xf=0.593 cm along the width, and
Yf=0.320 cm along the length.
• Eqns (8) and (9) give the E
and H plane radiation
patterns: ko=2π / λo=2.1
rad/cm
• The half power beamwidths
are given by eqns (10) and
(11) as: θBE=1.65 rad and
θBH=2.158 rad
• The directivity is calculated
from eqn(12) as: D= 6.933
dB
• Eqn (14) gives the BW as:
BW=7.9 %
This example can be extended
for all other materials. Table 1
gives the calculated parameters
associated with such materials.
It is clear from this table that Duroid
5880, Duroid 5870 and, Quartiz are
the best materials for proposed design
with broader bandwidth and better
mechanical characteristics than using
air.
Example two : Modified Shape
Microstrip Design (MSMSA)[16].
8. 7
Dielectric material RT Duroid 5880,
dielectric constant εr=2.2, loss
tangent<0.0009, operating frequency
(8-12) GHz, λo=3 cm, h=0.17 cm.
From Figure 4 broadband antenna
design needs to choose L, W1 and W2.
This can be done by the following
steps design procedure:
From Table 1, the actual length
L at 10 GHz for this dielectric is
L=0.8976 cm
• Eqn (6) gives W1 at 8 GHz
W1=1.48232 cm and W2
at12GHz
W2=0.988212
cm
• The feed point location as:
Xf=W1/2=0.74116 cm, and
Yf=L/2√ εreff=0.320 cm
• The ground plane dimensions
as:
L g=6 h + L =1.9176 cm ,
and Wg=6 h+W1=2.50232 cm
Table 2 shows the calculated
dimensions for different materials
compared to air case. This table is
used to get all results for MSA
performance.
5. SIMULATION AND
RESULTS
In this section, a documentation of
results is presented. These results are
obtained by using a design package
called Microwave Office version 3.22,
2000. The microwave office results
are compared with their
corresponding theoretical results.
These results are separated into two
categories: The first category includes
the simulation and test of RMSA with
single layer, probe fed and its
performance calculations (VSWR,
bandwidth, HPBW and, field pattern).
While the second category, includes
the simulation and test of the
suggested modified shape microstrip
antenna (MSMSA) and the effect of
variation of the feeding point with and
without adding the central shorting
pins[15].
a) Consider the RMSA that were
designed in previous sections, and
whose results were given in Table 1,
are tested using microwave office
package .
The selection of the correct material
for the broadband design is made.
Three types of substrate materials are
chosen. These substrate materials are
Duroid 5880, Quartiz, and Duroid
6006 and their dielectric constants are
2.2, 3.78 and 6.15 respectively. The
test shows that the bandwidth (for
VSWR≤2) in the operating X - band,
for Duroid 5880 is 9.7% and for
Quartiz is 15.5%, while for Duroid
6006 it is 1.3% [15]. Therefore the
choice was made on Duroid 5880 and
Quartiz, because they have a broader
BW than Duroid 6006.
Referring to Table 1, the original
feeding point of RMSA with substrate
material Duroid 5880 is (Xf = 0.593
cm, Yf= 0.320 cm) and, for Quartz is
(Xf = 0.34 cm, Yf = 0.25 cm) with an
operating frequency of 10 GHz. The
feeding will be shifted along X and Y
axis. From the original feeding point,
for Duroid 5880 it is by amount of
±0.038952 cm along X and ±0.044118
cm along Y, and for Quartz it is by
amount of ±0.048515 cm along X and
±0.034425 cm along Y.This shifted
gives a gain in the BW of the RMSA ,
for Duroid 5880, it is enhanced from
(9.7%) to (10.8%). While for Quartz,
the VSWR BW is enhanced from
(15.5%) to (16.1%). The optimum
value of shifting for Duroid 5880 is
toward positive X, while for Quartz it
is toward negative X taking into
9. 8
consideration the mismatching
problems.
The central shorting pin is added
to the rectangular patch, where its
feeding position is shifted. As can be
seen from Fig. 6 , there is a gain in
VSWR BW≤2 of the RMSA, when the
central shorting pin is used, because
the resonance size of the patch
increases. For substrate material
Duroid 5880 is enhanced the
bandwidth from 1080 MHz (10.8%) to
1160 MHz (11.6%) . It increases by an
amount of 80 MHz (0.8%). While
that for Quartz, the BW is enhanced
from 1610 MHz (16.1%) to 1740 MHz
(17.4%). It increases by an amount of
130 MHz (1.3%).
Figure 7 a,b shows the normalized
electric field in polar and rectangular
plots radiation pattern of the RMSA in
H-plane, with and without the central
shorting pin for Duroid 5880. HPBW
in H-plane which can be determined
from this figure as θBH= 69.3°. Fig
8a,b shows that in E-plane, with and
without the central shorting pin for
Duroid 5880. HPBW in E-plane is
θBE= 51.9° . Fig. 9 a,b shows the
correspond normalized radiated power
pattern in polar and rectangular plots.
It is clear, from these plots that the
central shorting pin, offers a small
degrading in the far field radiation
pattern, and gives a considerable
effects on bandwidth as seen in Fig. 6
.
b) Consider the proposed modified
shape microstrip antenna (MSMSA)
which gives improvement in the
radiation characteristics and
bandwidth over RMSA.
This MSMSA is also simulated and
tested using microwave office
package, with and without central
shorting pin, for the two substrate
materials the Duroid 5880 and
Quartz.
Fig. 10 shows the VSWR variation
with respect to frequency for the
modified shape patch with and
without central shorting pin, for
Duroid 5880 and Quartz . VSWR
BW≤2 of Duroid 5880 without central
shorting pin is 2.54 GHz (25.4%),
whereas with central shorting pin is
2.62 GHz (26.2%), while for Quartz
is enhanced from 2.39 GHz (23.9%),
to 3.09 GHz (30.9%)by using central
shorting pin.
Fig. 11a,b shows the electric field in
polar and rectangular plot, of the
Duroid 5880 (MSMSA) in H-plane,
with and without the central shorting
pin. HPBW are θBH= 57.4° and θBH=
59.6° respectively for the two cases.
Fig. 12 a,b shows the Electric field
plots in E-plane where θBE= 15.86°
for the two cases.
Fig. 13 a,b shows the normalized
radiated power pattern for MSMSA
in polar and rectangular plots, with
and without the central shorting pin
for Duroid 5880 .
It is clear that the central shorting
pin, gives a considerable effect on
bandwidth of MSA.
6. Conclusion
One of the main problems arises
with the operation of MSA is the
surface wave excitation. Reduction of
surface wave is done by adjusting the
substrate height with respect to the
dielectric constant substrate material.
The selection of substrate materials
used in this design processes is based
10. 9
on two materials, Duroid 5880 and,
Quartiz.
Broadening the bandwidth of the
rectangular microstrip antenna was
achieved by using a method of
lowering quality factor, shift feeding
point position, reactive loading and
by modification of the patch shape.
For substrate material Duroid 5880,
initial with 9.7% bandwidth with low
quality factor RMSA fed at original
feeding point getting as overall of
26.2% bandwidth with modification
in patch shape where reactive loading
was used. While for Quartz, initial
with 15.5% a percentage to be
enhanced to 30.9% by using shape
modification and, insertion of central
shorting pin. Table 3 shows the
enhancement in BW% for the
proposed types of MSA .
7. References
[1] COSTANTINE A. BALANIS,
"ANTENNA THEORY ANALYSIS
AND DESIGN", Wiley, 2nd edition,
Chapter 14, 1997.
[2] K. Rambabu, M. Alam, J.
Bornemann and M. A. Stuchly,
"Compact Wideband Dual-Polarized
Microstrip Patch Antenna", IEEE.
2004.
www.ece.uvic.ca/~jbornema/Conferen
ces/102-04aps-kabs.pdf.
[3] Chang won Jung and Franco De
Flaviis, " A Dual-Band Antenna for
WLAN Applications by Double
Rectangular Patch with 4-Bridges",
University of California, Irvine, CA,
USA. 1998.
[4] J. Ollikainen, M. Fischer and P.
Vainikainen, "Thin dual-resonant
stacked shorted patch antenna for
mobile communications", IEE.
Electronics Letters 35, number 6, pp
437-438, 1999.
[5] Jani Ollikainen and Pertti
Vainikainen, "Radiation and
Bandwidth Characteristics of Two
Planar Multistrip Antennas for Mobile
Communication Systems", IEEE
Vehicular Technology Conference.
Ottawa, Ontario, Canada, , volume 2,
pp. 1186-1190, 1998.
[6] R. W. Dearnley, " A Broadband
Transmission Line Model for a
Rectangular Microstrip Antenna"
IEEE Trans. , Antennas and
propagation, Vol. AP 37, No. 1, pp. 6
- 15, January 1989.
[7] James I.J & Hall P.s.,"
HANDBOOK OF MICROSTRIP
ANTENNAS", Vol. 1, Peter
Peregrinus Ltd., 1989.
[8] David W. Green, "Broadbanding
of Microstrip Antenna", 2002.
www.cwnp.com/learning_center/searc
h_details.php?doc_id=jbM80iLL-12k
.
[9] M . D . Deshpande, " Input
Impedance of Microstrip Antenna"
IEEE Trans. , Antennas and
propagation, Vol. AP 30, No. 4, pp.
645 - 650, July 1982.
[10] I. J. Bahl & P. Bhartia, "
Microstrip Antennas" Artech House,
1980.
[11] Zurcher, J-Francois and Gardiol,
F; "Broadband Patch Antenna"
Artech House, 1995.
[12] G. Kumar. & K. P. Ray,
"Broadband Microstrip Antennas",
Artech House, antennas and
propagations library. 2003
11. 10
[13] Ray, K. P., "Broadband, Dual-
Frequency and Compact Microstrip
Antennas",
Ph. D. thesis, Indian Institute of
Technology, Bombay, India, 1999.
[14] Debtosh Guha, "BROADBAND
DESIGN OF MICROSTRIP
ANTENNAS: Recent Trends and
Developments", Facta Universities
Series Vol. 3, No15, pp. 1083-1088,
2003.
[15] Basim K. Jar’alla "Design
Consideration, and Simulation of
Broadband Rectangular Microstrip
Antenna" M.Sc thesis , University of
Technology, Baghdad - Iraq, July
2005.
[16] S. Haider, "Microstrip Patch
Antennas for Broadband Indoor
Wireless Systems", University of
Auckland, USA, part 4, project report,
2003.
www.ece.auckland.ac.nz/p4p_2005/ar
chive/reports2003/pdfs/p11_iyou021.
pdf .
12. Eng.Tech.V0l.26,No1,2008
93
Fig. 1 Arrangement of arbitrary
shaped microstrip antenna (MSA)
(a) Top view
(b) Side view
Fig. 2 Top and side views of
rectangular microstrip antenna
(RMSA) with two Slots.
Substrate
Patch
Ground plane
Top View Side View
Feeding point
t
h
Substrate
Fig. 3 Feed positions on patch
13. 10
Fig. 4 Flow Chart of the
Main Design Process
Fig. 5
Modified Shape Microstrip Antenna.
Fig. 6 VSWR variation with
frequency for RMSA with shifted
input
feeding point for both cases
with and without central shorting pin
and for substrate materials
Duroid 5880 and Quartiz.
9.25 9.75 10.25
Frequency (GHz)
1
1.5
2
2.5
VSWR
9.39 GHz
2
9.36 GHz
2.01
9.43 GHz
2
9.44 GHz
2 10.5 G
2
10.1 GH
1.15
10 GHz
1.12
QUARTIZ REC SHAPE DESIGNED AT 10 GHz & FEEDING POINT SH
QUARIZ REC SHAPE DESIGNED AT 10 GHz & FEEDING
DUROID 5580 REC SHAPE DESIGNED AT 10 GHz &
DUROID 5580 REC SHAPE DESIGNED AT 10 GHz & FEEDING POIN
Design narrow BW
rectangular antenna at
center frequency of the
working band
Compact design modified shape that gives broader bandwidth
DESIGN REQUIREMENTS
Design narrow BW
rectangular antenna at
beginning frequency of
the working band
Design narrow BW
rectangular antenna at
end frequency of the
working band
Selection of substrate
With specified height to reduce surface wave excitation
W2W1 L
W1
W2
L Lg
Wg
Feeding
point
Central shorting
pin
14. 11
-90 -70 -50 -30 -10 10 30 50 70 90
phi (Deg)
ІEΦІn
0
0.16
0.33
0.49
0.67
1
E-Phi
DUROID 5880
SHIFTED POSITIVE X
E-Phi
0.83
-90 -70 -50 -30 -10 10 30 50 70 90
theta (Deg)
ІEθІn
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
E-Theta
DUROID 5880
SHIFTED POSITIVE X
E-Theta
DUROID 5880
SHIFTED POSITIVE X
WITH CENTRAL
SHORTING PIN
E-Phi
DUROID 5880
SHIFTED POSITIVE X
E-Phi
DUROID 5880
SHIFTED POSITIVE X
WITH CENTRAL
SHORTING PIN
0
-
-
-
-
-
-
-
-
-
-
-
-
- -
-
- -
1 1 1
1
1
1
1
1
1
9
8
7
6
5
4
3
21
0
-
-
-
-
-
-
-
-
-
-
-
-
- -
-
- -
1 1 16
1
1
1
12
1
10
9
8
7
6
5
4
3
21
E-Theta
DUROID 5880
SHIFTED POSITIVE X
E-Theta
DUROID 5880
SHIFTED POSITIVE X
WITH CENTRAL
SHORTING PIN
DUROID 5880
SHIFTED POSITIVE X
WITH CENTRAL
SHORTING PIN
Fig. 7 H-plane electric field radiation pattern E=f(θ) for RMSA for both
cases with and without central shorting pin and for substrate material
Duroid 5880 (a) normalized polar plot and, (b) normalized rectangular plot.
Fig. 8 E-plane, E=f(Φ) for RMSA for both cases with and without central shorting pin and
for substrate material Duroid 5880 (a)normalized polar plot, (b) normalized rectangular plot.
(a) (b)
(a) (b)
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
-140
-150
-160
-170
180
170 160 150 140
130
120
110
100
90
80
70
60
50
30
2010
RADIATED POWER (normalized)
P_Rad[1,1]
DUROID 5880 SHIFTED POSITIVE X
P_Rad[1,1]
DUROID 5880 SHIFTED POSITIVE
WITH CENTRAL SHORTING PIN
15. 12
8.25 8.75 9.25 9.75 10.25
Frequency (GHz)
1
1.5
2
2.5
9.5 GHz9.1 GHz8.37 GHz
8.75 GHz
1.4 10.2 GHz
1.32
QUARTIZ MODEFIED SHAPED WITH CENTR
QUARTIZ MODEFIED SHAPED, VSWR BW =
DUROID 5880 MODEFIED SHAPE, VSWR BW
DUROID 5880 MODEFIED SHAPE WITH CEN
Fig. 10 VSWR variations with frequency for mod
and without central shorting pin for substrate ma
-90 -70 -50 -30 -10 10 30 50 70 90
theta (Deg)
ІPrІn
0
0.154
0.31
0.4615
0.615
0.769
0.923
1 2.37 Deg
0.913
P_Rad[1,1]
DUROID 5880 SHIFTED POSITIVE X
P_Rad[1,1]
DUROID 5880 SHIFTED POSITIVE X
WITH CENTRAL SHORTING PINFig. 9 Radiated power pattern for RMSA for both cases with and without
central shorting pin and for Duroid 5880 (a) polar plot. (b) rectangular plot.
(b)
17. 14
Table 1 Results calculated for
various substrate materials at 10 GHz
for rectangular microstrip antenna.
Substrate εr h cm W cm εreff ∆L cm L cm Lg cm Wg cm %BW D dB
Duroid 5880 2.2 0.17 1.1859 1.9638 0.0864 0.8
Duroid 5870 2.33 0.17 1.1625 2.0657 0.0851 0.8
Quartz 3.78 0.17 0.9703 3.1792 0.0764 0.6
Duroid 6006 6.15 0.057 0.79333 5.462 0.025 0.
Alumina 9.8 0.057 0.6455 8.466 0.02395 0.4
Silicon 11.9 0.057 0.591 10.161 0.0236 0.4
Gallium
Arsenide
12.9 0.057 0.569 10.96 0.0235 0.4
Table 2 Calculated dimensions for
different materials
Table 3 Percentage bandwidth of
various types of MSA.
material εr h cm L cm W1 cm W2 cm Xf cm Yf cm Lg cm Wg cm
Air 1 0.17 1.268 1.875 1.25 0.9375 0.6340 2.288 2.895
Duroid
5880
2.2 0.17 0.8976 1.48232 0.988212 0.74116 0.3200 1.9176 2.50232
Duroid
5870
2.33 0.17 0.8735 1.4531 0.96873 0.72655 0.304 1.8935 2.4731
Quartiz 3.78 0.17 0.6885 1.213 0.809 0.6065 0.24 1.7085 2.233
Duroid6006 6.15 0.057 0.592 0.992 0.6611 0.496 0.127 0.934 1.334
Alumina 9.8 0.057 0.46764 0.8069 0.538 0.40345 0.0804 0.80964 1.1489
Silicon 11.9 0.057 0.4234 0.7383 0.4922 0.36915 0.066413 0.7654 1.0803
Gallium
Arsenide
12.9 0.057 0.4061 0.71123 0.4742 0.355615 0.06133 0.7481 1.05323
-90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90
Angle (Deg)
IPrIn
0
0.125
0.25
0.375
0.5
0.625
0.75
0.875
1 -0.249 Deg
0.969
P_Rad[1,1]
DUROID 5880 MODEFIED SHAPE
P_Rad[1,1]
DUROID 5880 MODEFIED SHAPE
WITH CENTRAL SHORTING PIN
18. 15
Substrate
material
Antenna type
Duroid
5880
Quartiz
Rectangular patch fed at original point
9.7%
BW
15.5%
BW
Rectangular patch shifted feeding point
10.8%
BW
16.1%
BW
Rectangular patch shifted feeding point
with central shorting pin
11.6%
BW
17.4%
BW
M o d i f i e d p a t c h s h a p e
25.4%
BW
23.9%
BW
M o d i f i e d p a t c h s h a p e
with central shorting pin
26.2%
BW
30.9%
BW