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A.A. Eldek
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ABSTRACT: A double rhombus antenna fed through a microstrip 180deg phase shifter is presented. The 180deg phase shifter is a novel design of microstrip-to-coplanar waveguide (CPW)-to-microstrip transition. The proposed phase shifter is obtained without changing the layer of the second microstrip line for an easy embedding into the feedline. Via holes are used to transfer the current from the top to the bottom substrate layer and vice versa. The antenna with the phase shifter is operating in a wide bandwidth from 5.7 and 18.6 GHz (106%), and provides stable endfire radiation patterns. This design is tested in a modified two-element array configuration and proved to have a wide usable bandwidth.
IEEE Transactions on Antennas and Propagation 07/2008; · 2.15 Impact Factor
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A.A. Eldek
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ABSTRACT: In this paper, a conventional microstrip-fed patch antenna that operates close to 10 GHz is modified to operate close to 2.5 GHz, without changing the dimensions of the antenna. First, the ground plane is replaced with a Uniplanar- Compact-Photonic-Band-Gab (UC-PBG) structure. Then, a backed conductor is placed close to the UC-PBG and connected to it through 4 vias. These two modifications are utilized to decrease the lower operating frequency of the antenna, which implicitly means decreasing the size of the antenna. Numerical study of the parameters of the UC-PBG structure is performed and presented to understand the effect of each parameter on the return loss of the antenna, and also to improve the size reduction factor. The small size of the proposed antenna makes it suitable for wireless communications applications.
Microelectronics, 2007. ICM 2007. Internatonal Conference on; 01/2008
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A.A. Eldek
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ABSTRACT: In this paper, an ultra wideband microstrip-fed printed antenna is presented for phased antenna array systems. The antenna consists of two parallel modified dipoles of different lengths. The regular dipole shape is modified to a quasi-rhombus shape by adding two triangular patches. Using two dipoles helps maintain stable radiation patterns close to their resonance frequencies. The proposed antenna provides endfire radiation patterns with high gain, high front-to-back ratio, low cross polarization level, wide beamwidth, and wide scanning angles in a wide bandwidth of 103%.
Radar Conference, 2007. EuRAD 2007. European; 11/2007
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A. A. Eldek
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ABSTRACT: A broadband microstrip-fed printed antenna is proposed for phased antenna array systems. The antenna consists of two parallel-modified dipoles of different lengths. The regular dipole shape is modified to a quasi-rhombus shape by adding two triangular patches. Using two dipoles helps maintain stable radiation patterns close to their resonance frequencies. A modified array configuration is proposed to further enhance the antenna radiation characteristics and usable bandwidth. Scanning capabilities are studied for a four-element array. The proposed antenna provides endfire radiation patterns with high gain, high front-to-back (F-to-B) ratio, low cross-polarization level, wide beamwidth, and wide scanning angles in a wide bandwidth of 103%
IEEE Transactions on Antennas and Propagation 02/2007; · 2.15 Impact Factor
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ABSTRACT: A modified printed bow-tie antenna is designed to simultaneously cover the operations in the C and X-bands from 5.5 to 12.5 GHz. The presented antenna has an end fire radiation pattern that makes it suitable for integration in single and dual polarized phased array systems. The antenna exhibits small size and wide bandwidth of 91%. The radiation characteristics are presented for a single element and a linear array of this antenna.
IEEE Transactions on Antennas and Propagation 10/2005; · 2.15 Impact Factor
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ABSTRACT: The dipole antenna is a simple and fundamental radiator and meets requirements for an antenna structure with a low profile and compact configuration. However, it cannot radiate efficiently near a perfect electric conductor (PEC) ground plane due to the reverse image currents. The paper presents the idea of using an EBG ground plane to improve the radiation efficiency of a nearby planar dipole antenna. The validity of the idea has been demonstrated by both FDTD simulations and measured results. The proposed antenna structure has a good potential for wireless communications, such as WLAN, and radar systems.
Antennas and Propagation Society International Symposium, 2005 IEEE; 08/2005
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ABSTRACT: A coplanar waveguide fed rectangular slot antenna tuned by a patch stub is designed and presented for ultra wideband band applications. The presented antenna exhibits a small size, a wide impedance bandwidth of 98%, and a 6 dB average gain.
Antennas and Propagation Society International Symposium, 2005 IEEE; 08/2005
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ABSTRACT: A novel printed antenna fed by a microstrip line is designed for wideband applications in the X-band. The antenna provides a wide bandwidth of over 60% relative to -10 dB, stable far field radiation characteristics in the entire operating band with relatively high gain, low cross polarization, wide beamwidth and good front-to-back ratio.
Antennas and Propagation Society International Symposium, 2005 IEEE; 08/2005
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ABSTRACT: The paper presents a modified printed bow-tie antenna for wideband phased array systems. The operating band of the proposed antenna simultaneously covers operations in the C and X-bands from 5.5 to 12.5 GHz. The antenna provides end fire radiation patterns, which makes it suitable for integration in single and dual polarized phased array systems.
Antennas and Propagation Society International Symposium, 2005 IEEE; 08/2005
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ABSTRACT: A dual tapered meander slot antenna (TMSA) is designed for use as an element in a phased array antenna system for RF and microwave sensors and radar applications. The novel design of dual TMSA element, excited by a coplanar waveguide (CPW) feed, provides a wide band and high efficiency characteristics with 50 Ω input impedance at 10 GHz operating frequency.
IEEE Transactions on Antennas and Propagation 08/2005; · 2.15 Impact Factor
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ABSTRACT: This paper presents a modified printed bow-tie antenna designed to simultaneously operate in the C and X-bands from 5.5 to 12.5 GHz. This new antenna design provides an end fire radiation pattern suitable for integration in single and dual polarized phased array systems. The antenna exhibits small size and wide bandwidth approaching 91%. The radiation characteristics are presented for a single element and for a linear array configuration.
Radar Conference, 2005 IEEE International; 06/2005
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ABSTRACT: Two printed Lotus antennas are designed for wideband personal wireless communication systems. The presented antennas exhibit wide bandwidths (60%), small in size, wide beamwidth, high front to back ratio, low cross polarization levels and relatively high gain.
Wireless Communications and Applied Computational Electromagnetics, 2005. IEEE/ACES International Conference on; 05/2005
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ABSTRACT: Novel designs of printed and slot antenna elements that support wideband applications for radar and wireless communication systems are presented in this paper. The common feature of these antenna elements is the dipole type shape while the feeding line is based on coplanar waveguide (CPW) or a microstrip line with a balun for phase correction. The two arms of the antennas may be placed on the same side of the substrate or on the opposite sides of the substrate with truncated ground plane. Several shapes of the antenna element are considered. Among these are the bow-tie, modified bow-tie, and lotus. Design procedure for the slot bow-tie antenna with a tuning stub is developed and verified for various frequency bands. In addition to presenting new antenna designs for wideband applications, multiple band-reconfigurable printed and slot antennas are also designed and experimental verifications at X-band are demonstrated for ideal switching configurations
Radio Science Conference, 2005. NRSC 2005. Proceedings of the Twenty-Second National; 04/2005
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ABSTRACT: This paper presents an antenna design for wideband wireless communications. The proposed antenna consists of a square slot and is fed by two orthogonal microstrip feedlines with U-shaped tuning stubs. The antenna operates on two wide bands. The bandwidth is 18% in the first band and 82% in the second one. It can sever the wireless communication applications that operate at 0.9, 1.8, 1.9 and 2.4 GHz and require wide band characteristics
Antennas and Propagation Society International Symposium, 2005 IEEE; 02/2005
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ABSTRACT: A novel printed antenna, fed by a microstrip line, has been designed for wideband wireless communication systems. The new antenna shows a wide -10dB bandwidth of over 60%. In addition to being small in size, the antenna exhibits stable far-field radiation characteristics in the entire operating band with relatively high gain, low cross polarization, wide beamwidth, and good front-to-back ratio.
IEEE Antennas and Propagation Magazine 01/2005; · 0.97 Impact Factor
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ABSTRACT: The paper presents a small triangle slot antenna fed by a coplanar waveguide. The antenna consists of a symmetrical triangle slot tuned by a metal stub and slot cap (hat) and exhibits a wide bandwidth of 53% relative to the X-band center frequency, with average gain of 7.5 dB and cross polarization level of -10 dB. In addition to being small in size, the coupling between two elements of this type of antenna is in the order of -15 dB or less, which makes it a good candidate for a phased array system.
Antennas and Propagation Society International Symposium, 2004. IEEE; 07/2004
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ABSTRACT: Printed bow-tie and bow-tie slot antennas are planar-type variations of the biconical antenna that has wideband characteristics. We present the effects of adding a tapered metal stub to a bow-tie slot antenna design to enhance the antenna bandwidth for X-band operation. Our study yields a design with 88% bandwidth relative to 10 GHz. The simulation and analysis are performed using the commercial computer software package, Momentum of Agilent Technologies, Advanced Design System (ADS). Verification of the ADS results is performed by using our developed finite difference time domain (FDTD) code and with measurements of the return loss from 7 to 15 GHz.
Radar Conference, 2004. Proceedings of the IEEE; 05/2004
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ABSTRACT: A bow-tie slot antenna fed by a coplanar waveguide is designed for wideband operation for radar applications. The new design exhibits 40 % bandwidth with center frequency around 11 GHz. One and two elements are designed analyzed and verification with measurements is presented.
Wireless Communication Technology, 2003. IEEE Topical Conference on; 11/2003
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ABSTRACT: In this paper a printed dipole antenna and three slot antennas are designed to operate at 10 GHz for use in radar systems. A parametric study of each antenna and comparison between their radiation properties including return loss, bandwidth, directivity, efficiency and radiation patterns for 6-element linear array are introduced. Microstrip slot antennas show wider bandwidth, less coupling and smaller antenna size compared with the traditional printed dipole.
Radar Conference, 2003. Proceedings of the 2003 IEEE; 06/2003
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ABSTRACT: Antenna designs are achieved for wideband operation by the use of a coplanar patch-slot antenna, fed by a coplanar waveguide. This design is easily tuned to operate at 2.45 and 5.75 GHz, with wide bandwidth for wireless systems. The operating frequency is controlled by modifying the patch dimensions. The return loss, input impedance, radiation pattern, directivity, gain, and efficiency of the proposed designs are computed and presented. A parametric study of the antenna is also introduced.
IEEE Antennas and Propagation Magazine 11/2002; · 0.97 Impact Factor
