Mohammad Amin Honarvar - Profile on Academia.edu (original) (raw)

Papers by Mohammad Amin Honarvar

Journal of Electromagnetic Waves and Applications, Feb 2, 2019

A novel Wilkinson power divider is presented in this paper for triple band operation. It comprise... more A novel Wilkinson power divider is presented in this paper for triple band operation. It comprises a П-shaped transmission-line coupled to a rectangular split ring resonator metamaterial structure. The μ-negative feature of the rectangular split ring resonator metamaterial structure is investigated by retrieving its constitutive parameters from the S-parameter response. To demonstrate the versatility of the proposed Wilkinson power divider it was designed to cover Bluetooth (2.4 GHz), WiMAX (3.5 GHz), and WLAN (5.2 GHz). The tri-band Wilkinson power divider was fabricated and its performance measured to verify the design. Good agreement between the measured and simulated data is obtained. Measured results show that the tri-band Wilkinson power divider has fractional bandwidth of 3.86%, 5.82%, and 3.89% at 2.4, 3.5, and 5.2 GHz, respectively. In addition, the rectangular split ring resonator metamaterial Wilkinson power divider has a small physical footprint (14 mm ×17.9 mm or 0.15λg×0.19λg), which is 60% smaller than conventional designs.

Design of a novel circularly polarized microstrip patch antenna using EBG structure

2009 Mediterrannean Microwave Symposium (MMS), 2009

In this paper a novel circularly polarized dual-feed microstrip patch antenna is proposed and als... more In this paper a novel circularly polarized dual-feed microstrip patch antenna is proposed and also electromagnetic band-gap (EBG) structures are utilized to enhance the antenna efficiency and bandwidth. The microstrip patch is a square with a chamfered corner and a cross-slot of equal arm lengths. It is fed by 50 ¿ two microstrip lines. The proposed antenna is designed to

Progress In Electromagnetics Research Letters, 2016

In this paper, a novel compact second-order quad-band bandpass filter (BPF) is applied based on a... more In this paper, a novel compact second-order quad-band bandpass filter (BPF) is applied based on a novel quintuple-mode stub-loaded trigonal ring resonator. Resonant characteristics are extracted by even-and odd-mode method. Designing procedure of resonant frequencies has also been presented. The last two resonant modes are utilized to cover a wide bandwidth for 5G WiFi application. The rest of other three resonant modes are used to form three passbands for GPS, WLAN and WiMAX applications. According to pseudo-interdigital structure four transmission zeros are generated among passbands to improve the band to band rejection and enhance the frequency selectivity. The measurement results agree well with the EM simulation ones.

A Novel High-Isolation Resistor-Less Millimeter-Wave Power Divider Based on Metamaterial Structures for 5G Applications

IEEE Transactions on Components, Packaging and Manufacturing Technology

In this article, a simple and effective method based on the metamaterial concept is proposed to a... more In this article, a simple and effective method based on the metamaterial concept is proposed to achieve very high isolation between the output ports of a millimeter-wave power divider (MWPD). The proposed MWPD is designed for use in 5G applications (28–32 GHz). In order to increase the isolation, three metamaterial rows are used, each row containing eight proposed unit cells. These metamaterial unit cells are loaded between two dielectric layers. By using this method and without isolating resistors, isolation is improved by more than 36 dB, as compared with a prototype power divider in which no metamaterial element was used. The maximum measured isolation is 43 dB at 30 GHz. The final dimensions of the proposed MWPD are <inline-formula> <tex-math notation="LaTeX">$8 \times 8\,\,\times0.582$ </tex-math></inline-formula> mm³ or <inline-formula> <tex-math notation="LaTeX">$0.9\,\,\lambda _{\mathbf {g}} \times 0.9\,\,\lambda _{\mathbf {g}} \times 0.08\,\,\lambda _{\mathbf {g}}$ </tex-math></inline-formula> where <inline-formula> <tex-math notation="LaTeX">$\lambda _{\mathbf {g}}$ </tex-math></inline-formula> is the guided wavelength at 30 GHz. The simplicity of design, its compactness, and most importantly, high isolation between output ports without any lumped resistor are the key advantages of the proposed MWPD.

In this article, an end-fire microstrip dipole antenna, with high gain and capability of operatin... more In this article, an end-fire microstrip dipole antenna, with high gain and capability of operating in millimeter-wave frequency band (57-64 GHz) is designed. The high gain of the antenna, with concept of negative permeability is achieved by the proposed metamaterial slabs embedded in horizontal plane of the dipole antenna. Each slab is loaded by a novel unit-cell. The result of the full-wave simulation presents the fact that the proposed design, would cause a better gain of 6.2 dBi in comparison with conventional dipole antenna without using metamaterial structures. In this structure, 28 metamaterial slabs from proposed unit-cells are used. These unit-cells are capable of creating two magnetic resonances that can play an important role to improve the gain in a wide frequency band. How to achieve this gain enhancement, depends on the number and decoration of metamaterial slabs around the antenna. These proposed metamaterial slabs are placed on top of the horizontal plane of the antenna, and also on the bottom of the antenna plane. This would cause the main lobe to stay still to the desired direction.

Coplanar-fed UWB Elliptical Patch Antenna with Notched Band Characteristics

This paper presents a novel band notched compact size antenna for ultra-wideband (UWB) communicat... more This paper presents a novel band notched compact size antenna for ultra-wideband (UWB) communication. The antenna consists of a elliptical metal patch and a 50› coplanar waveguide (CPW) transmission line. By etching two U and inverted U-shaped slots in the metal patch, band-stopped flltering properties are achieved. By attaching two parasitic U-shaped strip to the top layer of antenna stronger notch is obtained. The proposed antenna yields an impedance band width of 3.1{10.5GHz with VSWR < 2 except the band width of 5{6GHz for IEEE 802.11a. The stable omnidirectional patterns in H-plane and symmetric in E-plane are also obtained.

High‐gain, high‐isolation, and wideband millimetre‐wave closely spaced multiple‐input multiple‐output antenna with metamaterial wall and metamaterial superstrate for 5G applications

IET Microwaves, Antennas & Propagation

A novel compact-sized ultra-wideband (UWB) bandpass filter (BPF) is proposed in this paper. The p... more A novel compact-sized ultra-wideband (UWB) bandpass filter (BPF) is proposed in this paper. The proposed BPF is highly selective and is able to eliminate WLAN signals from 5.15-5.35 GHz, and downlink of X-band satellite communication signals from 7.25-7.75 GHz. Generally, a multiple-mode resonator (MMR), comprised of a U- shaped line, with two high impedance stubs connected to it, and one stepped impedance resonator placed in the center of the U-shaped line is used to generate five resonate modes in the desired band (range of 3.1- 10.6 GHz). Two transmission zeroes (TZs) are also placed to improve the bandage steepness. One of these TZs is with a lower cutoff frequency and the other TZ is with a higher cutoff frequency. A C-shaped open- circuited stub without adding any circuit size is parasitically coupled to the inner part of the U-shaped stub and can provide a narrow notched band at any desired frequency with appropriate bandwidth through the dimension of the parasitic element an...

This paper introduces a novel ultra-wideband (UWB) microstrip antenna having wireless local area ... more This paper introduces a novel ultra-wideband (UWB) microstrip antenna having wireless local area network band rejection characteristics. The proposed antenna is composed of a lip-shaped radiation patch being fed by a 50 Ω coplanar waveguide (CPW) feed line. The ground vertically continued to the two sides of the radiator. Thus, the substantial extra space adjacent to the radiator can be efficiently saved. The band rejection in the wireless local area networks (WLAN) (5.15-5.825GHz) is secured through etching the two symmetric C-shaped slots on ground plane to preclude interference between UWB and WLAN systems. The proposed antenna is of the size of 30×30×1.6 working within the range of 2.96 to 11.2 GHz with VSWR lower than 2 except in 5.15-5.825GHz band. Finally, the antenna is simulated and fabricated with nearly omnidirectional radiation patterns, stable gain and constant group delay in the operating band.

Gain Enhancement of Wideband Circularly Polarized UWB Antenna Using FSS

Radio Science

IETE Journal of Research

A novel miniature Wilkinson power divider (WPD) design is presented. This is achieved by substitu... more A novel miniature Wilkinson power divider (WPD) design is presented. This is achieved by substituting the quarter-wavelength transmission-lines constituting the WPD with an equivalent pair of parallel transmission-lines (PPTLs) that effectively reduce the circuit size of the WPD by 43% compared with a conventional design whose ground-plane is defected. Particle swarm optimization (PSO) technique is used to achieve size reduction. Meandering the transmission-lines further reduce the WPD size by 22%. The proposed WPD has overall dimensions of 9.38 × 11.51 mm 2 or 0.11 λg × 0.14 λg, which is compatible with the requirements imposed by portable personal wireless systems. Coupling between the parallel transmission-lines is shown to extend the operational bandwidth of the power divider to 3.2 GHz (0.8-4 GHz) for a return-loss better than 10 dB. Index Terms-Wilkinson power divider (WPD), pair of parallel transmission-lines (PPTLs) miniaturization, particle swarm optimization (PSO), defected ground structure (DGS).

Progress In Electromagnetics Research Letters

This paper presents a narrow-band bandpass filter (NBBPF) using three cylindrical dielectric reso... more This paper presents a narrow-band bandpass filter (NBBPF) using three cylindrical dielectric resonators (CDRs) placed on three rectangular metallic cavities (RMCs). Two U-shaped planar resonators located between RMCs are used to realize narrow-band response effectively. The 3 dB fractional bandwidth (FBW) of the proposed filter is 0.275%. The filter is designed for Xband (9.85 GHz), with 20 MHz bandwidth for radar, satellite, and medical accelerators applications. High Q-factor (Q-factor = 400) and low fabrication cost are other advantages of the proposed design. The proposed NBBPF was fabricated, and its performance was measured to verify the design. Good agreement between the measured and simulated data is obtained.

Progress In Electromagnetics Research C

In this paper, a compact tri-band microstrip filter is designed and fabricated for application in... more In this paper, a compact tri-band microstrip filter is designed and fabricated for application in wireless communication systems such as Bluetooth, WIMAX (World Wide Interoperability for Microwave Access), and WLAN (Wireless Local Area Network). In the proposed filter, three resonators, i.e., Stub-Loaded Resonator (SLR), Stepped Impedance Resonator (SIR), and Square Split Ring Resonator (SSRR), are used. The dimensions of the proposed filter are equal to 16.2 × 12.3 mm 2 or 0.219λ g × 0.166λ g. These dimensions indicate that the proposed structure has reduced the size by about 40% compared to the conventional samples. This is the main advantage of the proposed filter. Finally, in order to investigate analysis and simulations, the proposed filter is fabricated. The results prove correctness of the design, analysis, and simulations.

Gain enhancement and mutual coupling reduction of multiple‐intput multiple‐output antenna for millimeter‐wave applications using two types of novel metamaterial structures

International Journal of RF and Microwave Computer-Aided Engineering

TURKISH JOURNAL OF ELECTRICAL ENGINEERING & COMPUTER SCIENCES

In this article a thin hybrid multiband printed loop antenna is presented for application in mult... more In this article a thin hybrid multiband printed loop antenna is presented for application in multiple-input multiple-output (MIMO) systems. The proposed antenna has several advantages; for example, the pseudofilter feature of the proposed antenna is one of this antenna's advantages. Because of the antenna's width (9.5 mm), it can be used on the edges of the board. The first resonant frequency is generated by the original loop of the antenna. Incorporation of different embedded components, i.e. a subsidiary loop, extended ground-traces, parasitic patch, and the slits, results in the proposed antenna resonating as a multiband antenna. This antenna is adjusted in such a way that it resonant in WLAN (2.4 , 5.2 , and 5.8 GHz) and WiMAX (3.5 GHz) bands. Four antennas are used as a MIMO system that are sequentially and perpendicularly placed along the edges of the board. In conclusion, the antenna design is confirmed according to simulation results obtained from the constructed prototype and associated measuring results.

ETRI Journal

A novel class of planar metamaterial unit-cells consisting of a peace logo pattern is presented. ... more A novel class of planar metamaterial unit-cells consisting of a peace logo pattern is presented. A significant advantage of the proposed peace-logo planar metamaterial (PLPM) unit-cell over existing designs is its tunability, simplicity, and compatibility with microstrip structures. The theoretical analysis is founded on the famous transmission-line theory for the metamaterial concept. Then, the tunable dual-band two-sided PLPM (TSPLPM) unit-cell is designed by printing a similar PLPM pattern at the bottom of the substrate. The influence of the bottom PLPM pattern on the resonance frequencies of the unit-cell was analyzed by performing numerical simulations using CST Microwave Studio 2017 and HFSSv15 simulators. The results of the numerical simulations demonstrated that the proposed TSPLPM has the ability to control the resonance frequencies over 50 GHz-75 GHz for millimeterwave applications.

International Journal of Microwave and Wireless Technologies

The design of a novel microstrip ultra-wideband (UWB) bandpass filter with quad narrow notched-ba... more The design of a novel microstrip ultra-wideband (UWB) bandpass filter with quad narrow notched-band functionality is presented. The filter consists of a multi-mode resonator (MMR) constituted from two modified stepped-impedance stubs that generate six resonate modes, five of which are within the UWB passband where the sixth mode is used to extend the upper stopband of the filter. Two transmission zeroes are located at the 3-dB edge of the passband to enhance the filter's selectivity with a skirt factor of 0.955. The MMR is fed through asymmetric interdigital coupled-lines feed to produce controllable notched-band. Additional notched-bands are generated with a parasitic coupled line. The notched-bands are centered exactly to eliminate interference at 5.2 GHz (wireless local area network (WLAN)), 5.8 GHz (WLAN), 6.8 GHz (radio-frequency identification), and 8 GHz (X-band). Good agreement is obtained between simulation and measurement results. The highly compact filter has dimensio...

Journal of Electromagnetic Waves and Applications, Feb 2, 2019

A novel Wilkinson power divider is presented in this paper for triple band operation. It comprise... more A novel Wilkinson power divider is presented in this paper for triple band operation. It comprises a П-shaped transmission-line coupled to a rectangular split ring resonator metamaterial structure. The μ-negative feature of the rectangular split ring resonator metamaterial structure is investigated by retrieving its constitutive parameters from the S-parameter response. To demonstrate the versatility of the proposed Wilkinson power divider it was designed to cover Bluetooth (2.4 GHz), WiMAX (3.5 GHz), and WLAN (5.2 GHz). The tri-band Wilkinson power divider was fabricated and its performance measured to verify the design. Good agreement between the measured and simulated data is obtained. Measured results show that the tri-band Wilkinson power divider has fractional bandwidth of 3.86%, 5.82%, and 3.89% at 2.4, 3.5, and 5.2 GHz, respectively. In addition, the rectangular split ring resonator metamaterial Wilkinson power divider has a small physical footprint (14 mm ×17.9 mm or 0.15λg×0.19λg), which is 60% smaller than conventional designs.

Design of a novel circularly polarized microstrip patch antenna using EBG structure

2009 Mediterrannean Microwave Symposium (MMS), 2009

In this paper a novel circularly polarized dual-feed microstrip patch antenna is proposed and als... more In this paper a novel circularly polarized dual-feed microstrip patch antenna is proposed and also electromagnetic band-gap (EBG) structures are utilized to enhance the antenna efficiency and bandwidth. The microstrip patch is a square with a chamfered corner and a cross-slot of equal arm lengths. It is fed by 50 ¿ two microstrip lines. The proposed antenna is designed to

Progress In Electromagnetics Research Letters, 2016

In this paper, a novel compact second-order quad-band bandpass filter (BPF) is applied based on a... more In this paper, a novel compact second-order quad-band bandpass filter (BPF) is applied based on a novel quintuple-mode stub-loaded trigonal ring resonator. Resonant characteristics are extracted by even-and odd-mode method. Designing procedure of resonant frequencies has also been presented. The last two resonant modes are utilized to cover a wide bandwidth for 5G WiFi application. The rest of other three resonant modes are used to form three passbands for GPS, WLAN and WiMAX applications. According to pseudo-interdigital structure four transmission zeros are generated among passbands to improve the band to band rejection and enhance the frequency selectivity. The measurement results agree well with the EM simulation ones.

A Novel High-Isolation Resistor-Less Millimeter-Wave Power Divider Based on Metamaterial Structures for 5G Applications

IEEE Transactions on Components, Packaging and Manufacturing Technology

In this article, a simple and effective method based on the metamaterial concept is proposed to a... more In this article, a simple and effective method based on the metamaterial concept is proposed to achieve very high isolation between the output ports of a millimeter-wave power divider (MWPD). The proposed MWPD is designed for use in 5G applications (28–32 GHz). In order to increase the isolation, three metamaterial rows are used, each row containing eight proposed unit cells. These metamaterial unit cells are loaded between two dielectric layers. By using this method and without isolating resistors, isolation is improved by more than 36 dB, as compared with a prototype power divider in which no metamaterial element was used. The maximum measured isolation is 43 dB at 30 GHz. The final dimensions of the proposed MWPD are <inline-formula> <tex-math notation="LaTeX">$8 \times 8\,\,\times0.582$ </tex-math></inline-formula> mm³ or <inline-formula> <tex-math notation="LaTeX">$0.9\,\,\lambda _{\mathbf {g}} \times 0.9\,\,\lambda _{\mathbf {g}} \times 0.08\,\,\lambda _{\mathbf {g}}$ </tex-math></inline-formula> where <inline-formula> <tex-math notation="LaTeX">$\lambda _{\mathbf {g}}$ </tex-math></inline-formula> is the guided wavelength at 30 GHz. The simplicity of design, its compactness, and most importantly, high isolation between output ports without any lumped resistor are the key advantages of the proposed MWPD.

In this article, an end-fire microstrip dipole antenna, with high gain and capability of operatin... more In this article, an end-fire microstrip dipole antenna, with high gain and capability of operating in millimeter-wave frequency band (57-64 GHz) is designed. The high gain of the antenna, with concept of negative permeability is achieved by the proposed metamaterial slabs embedded in horizontal plane of the dipole antenna. Each slab is loaded by a novel unit-cell. The result of the full-wave simulation presents the fact that the proposed design, would cause a better gain of 6.2 dBi in comparison with conventional dipole antenna without using metamaterial structures. In this structure, 28 metamaterial slabs from proposed unit-cells are used. These unit-cells are capable of creating two magnetic resonances that can play an important role to improve the gain in a wide frequency band. How to achieve this gain enhancement, depends on the number and decoration of metamaterial slabs around the antenna. These proposed metamaterial slabs are placed on top of the horizontal plane of the antenna, and also on the bottom of the antenna plane. This would cause the main lobe to stay still to the desired direction.

Coplanar-fed UWB Elliptical Patch Antenna with Notched Band Characteristics

This paper presents a novel band notched compact size antenna for ultra-wideband (UWB) communicat... more This paper presents a novel band notched compact size antenna for ultra-wideband (UWB) communication. The antenna consists of a elliptical metal patch and a 50› coplanar waveguide (CPW) transmission line. By etching two U and inverted U-shaped slots in the metal patch, band-stopped flltering properties are achieved. By attaching two parasitic U-shaped strip to the top layer of antenna stronger notch is obtained. The proposed antenna yields an impedance band width of 3.1{10.5GHz with VSWR < 2 except the band width of 5{6GHz for IEEE 802.11a. The stable omnidirectional patterns in H-plane and symmetric in E-plane are also obtained.

High‐gain, high‐isolation, and wideband millimetre‐wave closely spaced multiple‐input multiple‐output antenna with metamaterial wall and metamaterial superstrate for 5G applications

IET Microwaves, Antennas & Propagation

A novel compact-sized ultra-wideband (UWB) bandpass filter (BPF) is proposed in this paper. The p... more A novel compact-sized ultra-wideband (UWB) bandpass filter (BPF) is proposed in this paper. The proposed BPF is highly selective and is able to eliminate WLAN signals from 5.15-5.35 GHz, and downlink of X-band satellite communication signals from 7.25-7.75 GHz. Generally, a multiple-mode resonator (MMR), comprised of a U- shaped line, with two high impedance stubs connected to it, and one stepped impedance resonator placed in the center of the U-shaped line is used to generate five resonate modes in the desired band (range of 3.1- 10.6 GHz). Two transmission zeroes (TZs) are also placed to improve the bandage steepness. One of these TZs is with a lower cutoff frequency and the other TZ is with a higher cutoff frequency. A C-shaped open- circuited stub without adding any circuit size is parasitically coupled to the inner part of the U-shaped stub and can provide a narrow notched band at any desired frequency with appropriate bandwidth through the dimension of the parasitic element an...

This paper introduces a novel ultra-wideband (UWB) microstrip antenna having wireless local area ... more This paper introduces a novel ultra-wideband (UWB) microstrip antenna having wireless local area network band rejection characteristics. The proposed antenna is composed of a lip-shaped radiation patch being fed by a 50 Ω coplanar waveguide (CPW) feed line. The ground vertically continued to the two sides of the radiator. Thus, the substantial extra space adjacent to the radiator can be efficiently saved. The band rejection in the wireless local area networks (WLAN) (5.15-5.825GHz) is secured through etching the two symmetric C-shaped slots on ground plane to preclude interference between UWB and WLAN systems. The proposed antenna is of the size of 30×30×1.6 working within the range of 2.96 to 11.2 GHz with VSWR lower than 2 except in 5.15-5.825GHz band. Finally, the antenna is simulated and fabricated with nearly omnidirectional radiation patterns, stable gain and constant group delay in the operating band.

Gain Enhancement of Wideband Circularly Polarized UWB Antenna Using FSS

Radio Science

IETE Journal of Research

A novel miniature Wilkinson power divider (WPD) design is presented. This is achieved by substitu... more A novel miniature Wilkinson power divider (WPD) design is presented. This is achieved by substituting the quarter-wavelength transmission-lines constituting the WPD with an equivalent pair of parallel transmission-lines (PPTLs) that effectively reduce the circuit size of the WPD by 43% compared with a conventional design whose ground-plane is defected. Particle swarm optimization (PSO) technique is used to achieve size reduction. Meandering the transmission-lines further reduce the WPD size by 22%. The proposed WPD has overall dimensions of 9.38 × 11.51 mm 2 or 0.11 λg × 0.14 λg, which is compatible with the requirements imposed by portable personal wireless systems. Coupling between the parallel transmission-lines is shown to extend the operational bandwidth of the power divider to 3.2 GHz (0.8-4 GHz) for a return-loss better than 10 dB. Index Terms-Wilkinson power divider (WPD), pair of parallel transmission-lines (PPTLs) miniaturization, particle swarm optimization (PSO), defected ground structure (DGS).

Progress In Electromagnetics Research Letters

This paper presents a narrow-band bandpass filter (NBBPF) using three cylindrical dielectric reso... more This paper presents a narrow-band bandpass filter (NBBPF) using three cylindrical dielectric resonators (CDRs) placed on three rectangular metallic cavities (RMCs). Two U-shaped planar resonators located between RMCs are used to realize narrow-band response effectively. The 3 dB fractional bandwidth (FBW) of the proposed filter is 0.275%. The filter is designed for Xband (9.85 GHz), with 20 MHz bandwidth for radar, satellite, and medical accelerators applications. High Q-factor (Q-factor = 400) and low fabrication cost are other advantages of the proposed design. The proposed NBBPF was fabricated, and its performance was measured to verify the design. Good agreement between the measured and simulated data is obtained.

Progress In Electromagnetics Research C

In this paper, a compact tri-band microstrip filter is designed and fabricated for application in... more In this paper, a compact tri-band microstrip filter is designed and fabricated for application in wireless communication systems such as Bluetooth, WIMAX (World Wide Interoperability for Microwave Access), and WLAN (Wireless Local Area Network). In the proposed filter, three resonators, i.e., Stub-Loaded Resonator (SLR), Stepped Impedance Resonator (SIR), and Square Split Ring Resonator (SSRR), are used. The dimensions of the proposed filter are equal to 16.2 × 12.3 mm 2 or 0.219λ g × 0.166λ g. These dimensions indicate that the proposed structure has reduced the size by about 40% compared to the conventional samples. This is the main advantage of the proposed filter. Finally, in order to investigate analysis and simulations, the proposed filter is fabricated. The results prove correctness of the design, analysis, and simulations.

Gain enhancement and mutual coupling reduction of multiple‐intput multiple‐output antenna for millimeter‐wave applications using two types of novel metamaterial structures

International Journal of RF and Microwave Computer-Aided Engineering

TURKISH JOURNAL OF ELECTRICAL ENGINEERING & COMPUTER SCIENCES

In this article a thin hybrid multiband printed loop antenna is presented for application in mult... more In this article a thin hybrid multiband printed loop antenna is presented for application in multiple-input multiple-output (MIMO) systems. The proposed antenna has several advantages; for example, the pseudofilter feature of the proposed antenna is one of this antenna's advantages. Because of the antenna's width (9.5 mm), it can be used on the edges of the board. The first resonant frequency is generated by the original loop of the antenna. Incorporation of different embedded components, i.e. a subsidiary loop, extended ground-traces, parasitic patch, and the slits, results in the proposed antenna resonating as a multiband antenna. This antenna is adjusted in such a way that it resonant in WLAN (2.4 , 5.2 , and 5.8 GHz) and WiMAX (3.5 GHz) bands. Four antennas are used as a MIMO system that are sequentially and perpendicularly placed along the edges of the board. In conclusion, the antenna design is confirmed according to simulation results obtained from the constructed prototype and associated measuring results.

ETRI Journal

A novel class of planar metamaterial unit-cells consisting of a peace logo pattern is presented. ... more A novel class of planar metamaterial unit-cells consisting of a peace logo pattern is presented. A significant advantage of the proposed peace-logo planar metamaterial (PLPM) unit-cell over existing designs is its tunability, simplicity, and compatibility with microstrip structures. The theoretical analysis is founded on the famous transmission-line theory for the metamaterial concept. Then, the tunable dual-band two-sided PLPM (TSPLPM) unit-cell is designed by printing a similar PLPM pattern at the bottom of the substrate. The influence of the bottom PLPM pattern on the resonance frequencies of the unit-cell was analyzed by performing numerical simulations using CST Microwave Studio 2017 and HFSSv15 simulators. The results of the numerical simulations demonstrated that the proposed TSPLPM has the ability to control the resonance frequencies over 50 GHz-75 GHz for millimeterwave applications.

International Journal of Microwave and Wireless Technologies

The design of a novel microstrip ultra-wideband (UWB) bandpass filter with quad narrow notched-ba... more The design of a novel microstrip ultra-wideband (UWB) bandpass filter with quad narrow notched-band functionality is presented. The filter consists of a multi-mode resonator (MMR) constituted from two modified stepped-impedance stubs that generate six resonate modes, five of which are within the UWB passband where the sixth mode is used to extend the upper stopband of the filter. Two transmission zeroes are located at the 3-dB edge of the passband to enhance the filter's selectivity with a skirt factor of 0.955. The MMR is fed through asymmetric interdigital coupled-lines feed to produce controllable notched-band. Additional notched-bands are generated with a parasitic coupled line. The notched-bands are centered exactly to eliminate interference at 5.2 GHz (wireless local area network (WLAN)), 5.8 GHz (WLAN), 6.8 GHz (radio-frequency identification), and 8 GHz (X-band). Good agreement is obtained between simulation and measurement results. The highly compact filter has dimensio...