Ieee Transactions on Antennas and Propagation, 2015
ABSTRACT A novel ultrathin slot-based transmitarray antenna is presented. The related unit cell c... more ABSTRACT A novel ultrathin slot-based transmitarray antenna is presented. The related unit cell consists of two thin dielectric layers placed on top of each other, with annular ring slots placed on the outer layers and a PBG element placed on the common interface. The combination of the two annular ring slots and the PBG element acts as a bandpass filter for the transmitted wave. The design of the elements can be carried out through a simple circuit-based analysis approach. The proposed two-layer structure, the unit cell, has a thickness of 0.033λo and provides the required 360° of phase shift. Furthermore, over the bandwidth, the unit cell can have up to 7° of phase error for incident angles of up to 50°. The unit cell and the full transmitarray prototype are fabricated, and the results were compared with simulation and discussed. The full transmitarray has -1 dB gain bandwidth of 5.7% and efficiency of 38% at the center frequency. The structure is simulated via HFSS and CST software package.
A full-wave analysis is presented for several stacked rectangular patch antennas, including anten... more A full-wave analysis is presented for several stacked rectangular patch antennas, including antennas with two equal patches of accurately defined and displaced edges. The analysis, which is based on the spectral domain technique, makes use of the electric field integral equation in conjunction with Galerkin's method for converting this equation to a set of linear equations. The effect of patch size on resonant frequencies, bandwidth, and input impedances is also investigated. The results obtained are verified experimentally.
IEEE Antennas and Wireless Propagation Letters, 2014
First of all, the authors appreciate the IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS Editorial... more First of all, the authors appreciate the IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS Editorial Board for giving us a chance to reply to the comments of . Also, we would like to thank the authors who did the additional analysis in [1] and gave us the opportunity for clarification of our paper novelty more and more.
Proceedings of the 2012 IEEE International Symposium on Antennas and Propagation, 2012
ABSTRACT A compact omnidirectional printed patch dipole antenna for RFID applications is presente... more ABSTRACT A compact omnidirectional printed patch dipole antenna for RFID applications is presented. To reduce the size of the antenna, the radiating elements of the quasi-Yagi antenna is loaded by Artificial Transmission Line (ATL). The proposed antenna operates at 915 MHz with 66% size reduction. Finally, the designed RFID antenna is fabricated and tested. The experimental data are in good agreement with the simulation results.
IEEE Transactions on Antennas and Propagation, 2015
ABSTRACT A novel metallic multi-band frequency selective surface (FSS) is presented. The proposed... more ABSTRACT A novel metallic multi-band frequency selective surface (FSS) is presented. The proposed FSS structure has operation bands from closely spaced to far from each other (wide range of band ratio) and has high selectivity at each operation band. The unit cell comprises four small square slots, each loaded with multiple stub resonators. The stubs are placed in each slot in such a way that the unit cell response to both TE and TM polarizations are the same. To miniaturize the unit cell and cover the lower frequency range, each stub resonator is terminated with a U-shaped section. The length of each stubs within the slot determine the resonant frequency of each passbands. The band ratio can be set from 1.09 (close to each other) up to 2.35 (far from each other). Single, dual, triple and quad band FSS structures are designed and simulated through HFSS software package. The fabricated dual-band unit cell shows that the proposed FSS structure can provide two close to each other bands, 9.8 and 10.9 GHz. Also, the measured results of a fabricated dual-band 17 x 17 FSS array show a relatively stable response to variations of incidence angle and polarization state.
IEEE Transactions on Antennas and Propagation, 2015
ABSTRACT A novel ultrathin slot-based transmitarray antenna is presented. The related unit cell c... more ABSTRACT A novel ultrathin slot-based transmitarray antenna is presented. The related unit cell consists of two thin dielectric layers placed on top of each other, with annular ring slots placed on the outer layers and a PBG element placed on the common interface. The combination of the two annular ring slots and the PBG element acts as a bandpass filter for the transmitted wave. The design of the elements can be carried out through a simple circuit-based analysis approach. The proposed two-layer structure, the unit cell, has a thickness of 0.033λo and provides the required 360° of phase shift. Furthermore, over the bandwidth, the unit cell can have up to 7° of phase error for incident angles of up to 50°. The unit cell and the full transmitarray prototype are fabricated, and the results were compared with simulation and discussed. The full transmitarray has -1 dB gain bandwidth of 5.7% and efficiency of 38% at the center frequency. The structure is simulated via HFSS and CST software package.
A Compact printed UWB slot antenna with tuneable extra band is presented in this paper. The penta... more A Compact printed UWB slot antenna with tuneable extra band is presented in this paper. The pentagonal slot antenna that covers the UWB band, 3.1 to 10.6 GHz, is fed by a semi circular patch. To create an extra band, an inverted U-shaped strip is attached to the upper part of the slot. By changing the length of this strip
In this paper, the characteristics of an L probe fed planar rectangular patch antenna mounted on ... more In this paper, the characteristics of an L probe fed planar rectangular patch antenna mounted on a cylindrical surface for circular polarization is investigated. To obtain a large bandwidth an L probe feed is used which is in the shape of a fork attached to a coaxial cable and is placed under a corner of the patch antenna. Simulation results, obtained via HFSS, on the return loss and radiation pattern of the antenna for circular polarization are presented. Results show an impedance bandwidth of 74.6%, an average gain of 7.5 dBi with stable radiation patterns across the entire passband and a bandwidth of 58% for AR < 3 dB.
Progress In Electromagnetics Research, Jan 1, 2009
In this paper, a linear series fed Yagi-like antenna array is introduced leading to an end-fire f... more In this paper, a linear series fed Yagi-like antenna array is introduced leading to an end-fire fan beam with low sidelobe level, SLL, high front to back ratio, F/B, and wide impedance bandwidth. The array can provide −29 dB SLL at centre frequency of 16.26 GHz, −20 dB SLL bandwidth of 7.5%, 23 dB F/B and 10.6% impedance bandwidth. Further improvement in SLL can be achieved by extending narrow strips from the finite ground plane of the antenna structure leading to some −32 dB SLL at centre frequency and a −20 dB SLL bandwidth of 8.7%. To verify the accuracy of the simulation results, both of the arrays are fabricated and tested. Finally, to show the applicability of the proposed design, the linear end-fire array of the above are stacked on top of each other and simulation results for a 2-D phased array are provided.
2012 6th European Conference on Antennas and Propagation (EUCAP), 2012
ABSTRACT This work presents a small size multiband antenna suitable for GPS, WLAN and WiMAX Appli... more ABSTRACT This work presents a small size multiband antenna suitable for GPS, WLAN and WiMAX Applications. The antenna has three branches that the modified branches consist of the straight branch that a bent stub has been added to the end of it. Also new design for defected ground structure is used to improve the impedance matching of the antenna. The omnidirectional radiation pattern and good gain with impedance matching below -10 dB over all frequency bands have been achieved. It was found that the results of simulations and measurements agree well over each separated frequency bands.
20th Iranian Conference on Electrical Engineering (ICEE2012), 2012
ABSTRACT Design of a compact and simple coplanar waveguide (CPW) fed printed monopole antenna for... more ABSTRACT Design of a compact and simple coplanar waveguide (CPW) fed printed monopole antenna for ultra wideband (UWB) application with multi band-notches is presented. The band notches are created by placing modified U-shaped (MU) slots on the rectangular radiating patch. The narrow width of the MU slots and the low mutual coupling that exists between the slots, allows several slots to be placed on top of each other to create multiple band notches over the UWB range. The proposed antenna has a compact size of 26 × 30 mm2. Return loss and radiation characteristics of the antenna with various configurations of the MU-slots are studied. The antenna with quad-band notches present good rejections over the 3.3-3.6 GHz band (covering IEEE 802.16 WiMAX system), 5.15-5.35 GHz band (WiMAX applications), 5.725-5.825 GHz band (WLAN) and also 7.2 GHz for some C-band satellite communication systems. The antenna exhibits omnidirectional radiation coverage with its gain significantly reduced at the notched frequency bands. An equivalent circuit model for the antenna is presented. Measured and simulated results are provided and compared.
6th International Symposium on Telecommunications (IST), 2012
ABSTRACT In this paper, a novel microstrip array antenna to achieve some specific contoured beam ... more ABSTRACT In this paper, a novel microstrip array antenna to achieve some specific contoured beam is presented. The proposed antenna produces three directional main beams which is a consequence of its particular layout. The antenna is suggested to be mounted on High Altitude Platforms (HAPs) to provide the desirable coverage (e.g. three separated islands). Using developed software, enables us to obtain the footprint of antenna on the ground. Furthermore, a study on channel capacity enhancement, employing the proposed antenna is carried out which clarify the profit of using this contoured beam antenna.
A novel design of a circularly polarized CPW-fed antenna for WiMAX/WLAN application is presented.... more A novel design of a circularly polarized CPW-fed antenna for WiMAX/WLAN application is presented. The antenna consists of a CPW-feed structure, two square slots around both sides of the feed and two interleaved parasitic resonance strips inserted within each of the square slots. The proposed antenna gives circular polarization at the centre frequency of 2385 MHz with 3 dB axial ratio bandwidth of about 3.77% and impedance bandwidth of 13.39%. The designed antenna has a small size of 30×40 mm 2 .
Ieee Transactions on Antennas and Propagation, 2015
ABSTRACT A novel ultrathin slot-based transmitarray antenna is presented. The related unit cell c... more ABSTRACT A novel ultrathin slot-based transmitarray antenna is presented. The related unit cell consists of two thin dielectric layers placed on top of each other, with annular ring slots placed on the outer layers and a PBG element placed on the common interface. The combination of the two annular ring slots and the PBG element acts as a bandpass filter for the transmitted wave. The design of the elements can be carried out through a simple circuit-based analysis approach. The proposed two-layer structure, the unit cell, has a thickness of 0.033λo and provides the required 360° of phase shift. Furthermore, over the bandwidth, the unit cell can have up to 7° of phase error for incident angles of up to 50°. The unit cell and the full transmitarray prototype are fabricated, and the results were compared with simulation and discussed. The full transmitarray has -1 dB gain bandwidth of 5.7% and efficiency of 38% at the center frequency. The structure is simulated via HFSS and CST software package.
A full-wave analysis is presented for several stacked rectangular patch antennas, including anten... more A full-wave analysis is presented for several stacked rectangular patch antennas, including antennas with two equal patches of accurately defined and displaced edges. The analysis, which is based on the spectral domain technique, makes use of the electric field integral equation in conjunction with Galerkin's method for converting this equation to a set of linear equations. The effect of patch size on resonant frequencies, bandwidth, and input impedances is also investigated. The results obtained are verified experimentally.
IEEE Antennas and Wireless Propagation Letters, 2014
First of all, the authors appreciate the IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS Editorial... more First of all, the authors appreciate the IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS Editorial Board for giving us a chance to reply to the comments of . Also, we would like to thank the authors who did the additional analysis in [1] and gave us the opportunity for clarification of our paper novelty more and more.
Proceedings of the 2012 IEEE International Symposium on Antennas and Propagation, 2012
ABSTRACT A compact omnidirectional printed patch dipole antenna for RFID applications is presente... more ABSTRACT A compact omnidirectional printed patch dipole antenna for RFID applications is presented. To reduce the size of the antenna, the radiating elements of the quasi-Yagi antenna is loaded by Artificial Transmission Line (ATL). The proposed antenna operates at 915 MHz with 66% size reduction. Finally, the designed RFID antenna is fabricated and tested. The experimental data are in good agreement with the simulation results.
IEEE Transactions on Antennas and Propagation, 2015
ABSTRACT A novel metallic multi-band frequency selective surface (FSS) is presented. The proposed... more ABSTRACT A novel metallic multi-band frequency selective surface (FSS) is presented. The proposed FSS structure has operation bands from closely spaced to far from each other (wide range of band ratio) and has high selectivity at each operation band. The unit cell comprises four small square slots, each loaded with multiple stub resonators. The stubs are placed in each slot in such a way that the unit cell response to both TE and TM polarizations are the same. To miniaturize the unit cell and cover the lower frequency range, each stub resonator is terminated with a U-shaped section. The length of each stubs within the slot determine the resonant frequency of each passbands. The band ratio can be set from 1.09 (close to each other) up to 2.35 (far from each other). Single, dual, triple and quad band FSS structures are designed and simulated through HFSS software package. The fabricated dual-band unit cell shows that the proposed FSS structure can provide two close to each other bands, 9.8 and 10.9 GHz. Also, the measured results of a fabricated dual-band 17 x 17 FSS array show a relatively stable response to variations of incidence angle and polarization state.
IEEE Transactions on Antennas and Propagation, 2015
ABSTRACT A novel ultrathin slot-based transmitarray antenna is presented. The related unit cell c... more ABSTRACT A novel ultrathin slot-based transmitarray antenna is presented. The related unit cell consists of two thin dielectric layers placed on top of each other, with annular ring slots placed on the outer layers and a PBG element placed on the common interface. The combination of the two annular ring slots and the PBG element acts as a bandpass filter for the transmitted wave. The design of the elements can be carried out through a simple circuit-based analysis approach. The proposed two-layer structure, the unit cell, has a thickness of 0.033λo and provides the required 360° of phase shift. Furthermore, over the bandwidth, the unit cell can have up to 7° of phase error for incident angles of up to 50°. The unit cell and the full transmitarray prototype are fabricated, and the results were compared with simulation and discussed. The full transmitarray has -1 dB gain bandwidth of 5.7% and efficiency of 38% at the center frequency. The structure is simulated via HFSS and CST software package.
A Compact printed UWB slot antenna with tuneable extra band is presented in this paper. The penta... more A Compact printed UWB slot antenna with tuneable extra band is presented in this paper. The pentagonal slot antenna that covers the UWB band, 3.1 to 10.6 GHz, is fed by a semi circular patch. To create an extra band, an inverted U-shaped strip is attached to the upper part of the slot. By changing the length of this strip
In this paper, the characteristics of an L probe fed planar rectangular patch antenna mounted on ... more In this paper, the characteristics of an L probe fed planar rectangular patch antenna mounted on a cylindrical surface for circular polarization is investigated. To obtain a large bandwidth an L probe feed is used which is in the shape of a fork attached to a coaxial cable and is placed under a corner of the patch antenna. Simulation results, obtained via HFSS, on the return loss and radiation pattern of the antenna for circular polarization are presented. Results show an impedance bandwidth of 74.6%, an average gain of 7.5 dBi with stable radiation patterns across the entire passband and a bandwidth of 58% for AR < 3 dB.
Progress In Electromagnetics Research, Jan 1, 2009
In this paper, a linear series fed Yagi-like antenna array is introduced leading to an end-fire f... more In this paper, a linear series fed Yagi-like antenna array is introduced leading to an end-fire fan beam with low sidelobe level, SLL, high front to back ratio, F/B, and wide impedance bandwidth. The array can provide −29 dB SLL at centre frequency of 16.26 GHz, −20 dB SLL bandwidth of 7.5%, 23 dB F/B and 10.6% impedance bandwidth. Further improvement in SLL can be achieved by extending narrow strips from the finite ground plane of the antenna structure leading to some −32 dB SLL at centre frequency and a −20 dB SLL bandwidth of 8.7%. To verify the accuracy of the simulation results, both of the arrays are fabricated and tested. Finally, to show the applicability of the proposed design, the linear end-fire array of the above are stacked on top of each other and simulation results for a 2-D phased array are provided.
2012 6th European Conference on Antennas and Propagation (EUCAP), 2012
ABSTRACT This work presents a small size multiband antenna suitable for GPS, WLAN and WiMAX Appli... more ABSTRACT This work presents a small size multiband antenna suitable for GPS, WLAN and WiMAX Applications. The antenna has three branches that the modified branches consist of the straight branch that a bent stub has been added to the end of it. Also new design for defected ground structure is used to improve the impedance matching of the antenna. The omnidirectional radiation pattern and good gain with impedance matching below -10 dB over all frequency bands have been achieved. It was found that the results of simulations and measurements agree well over each separated frequency bands.
20th Iranian Conference on Electrical Engineering (ICEE2012), 2012
ABSTRACT Design of a compact and simple coplanar waveguide (CPW) fed printed monopole antenna for... more ABSTRACT Design of a compact and simple coplanar waveguide (CPW) fed printed monopole antenna for ultra wideband (UWB) application with multi band-notches is presented. The band notches are created by placing modified U-shaped (MU) slots on the rectangular radiating patch. The narrow width of the MU slots and the low mutual coupling that exists between the slots, allows several slots to be placed on top of each other to create multiple band notches over the UWB range. The proposed antenna has a compact size of 26 × 30 mm2. Return loss and radiation characteristics of the antenna with various configurations of the MU-slots are studied. The antenna with quad-band notches present good rejections over the 3.3-3.6 GHz band (covering IEEE 802.16 WiMAX system), 5.15-5.35 GHz band (WiMAX applications), 5.725-5.825 GHz band (WLAN) and also 7.2 GHz for some C-band satellite communication systems. The antenna exhibits omnidirectional radiation coverage with its gain significantly reduced at the notched frequency bands. An equivalent circuit model for the antenna is presented. Measured and simulated results are provided and compared.
6th International Symposium on Telecommunications (IST), 2012
ABSTRACT In this paper, a novel microstrip array antenna to achieve some specific contoured beam ... more ABSTRACT In this paper, a novel microstrip array antenna to achieve some specific contoured beam is presented. The proposed antenna produces three directional main beams which is a consequence of its particular layout. The antenna is suggested to be mounted on High Altitude Platforms (HAPs) to provide the desirable coverage (e.g. three separated islands). Using developed software, enables us to obtain the footprint of antenna on the ground. Furthermore, a study on channel capacity enhancement, employing the proposed antenna is carried out which clarify the profit of using this contoured beam antenna.
A novel design of a circularly polarized CPW-fed antenna for WiMAX/WLAN application is presented.... more A novel design of a circularly polarized CPW-fed antenna for WiMAX/WLAN application is presented. The antenna consists of a CPW-feed structure, two square slots around both sides of the feed and two interleaved parasitic resonance strips inserted within each of the square slots. The proposed antenna gives circular polarization at the centre frequency of 2385 MHz with 3 dB axial ratio bandwidth of about 3.77% and impedance bandwidth of 13.39%. The designed antenna has a small size of 30×40 mm 2 .
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