This paper presents the design and development of two element slot loaded rectangular microstrip array antenna for dual band operation. The dual bands are achieved at X and Ku band of frequencies. Effect of slots of different shapes embedded on the array elements is studied experimentally for enhancing the bandwidth. It is found that by using L-shape complementary slots on the array elements an...

The packet throughput is analyzed for a slow FH/SSMA packet radio network with adapt ivc o i i t e r i r m array and packet combznzng in a Rayleigh fading channel with shadowing. The packet throughput is defined as the average number of captured packets per slot. To enhance the throughput performance, the adaptive antenna array and packet combining are employed. As a random access protocol, slo...

A novel frequency reconfigurable slot antenna is designed for cognitive radio system. In cognitive radio system the two antennas are required one is a wideband antenna and another is frequency reconfigurable antenna. In this work a frequency reconfigurable slot antenna is designed between the switchable frequency range i.e 7.347.96 GHz at eight different frequency band and capable to operate si...

detection of stealth targets calls for employment of high-power radars which itself relies on usage of high-gain antennas like large parabolic reflectors. in the past few years, using of an array with many small reflectors instead of a large reflector antenna has been considered. this method provides enhanced eirp by a factor of n2 where n is the number of array antennas. regarding improvement ...

In this paper, a single-chip impulse antenna array is presented that performs spatial combining of picosecond impulses radiated from 8 elements. A new broadband beamforming architecture is introduced that controls the timing of impulses radiated from each antenna by delaying a trigger signal, with resolution steps of 300fsec. This method eliminates the distortive and narrowband effects of delay...

High gain antennas have many applications in wireless communication systems as they produce focused and narrow beamwidth, which allow for more precise targeting of the signal. Therefore, various gain enhancement techniques for antennas have been studied in the past decades [1–21]. Specifically there are three important methods to achieve this purpose: (1) Using antenna array, (2) Adding superst...

A new meta-surface structure (MSS) with a near-zero refractive index (NZRI) is proposed to enhance the performance of a square loop antenna array. The main challenge to improve the antenna performance is increment of the overall antenna volume that is mitigated by assimilating the planar NZRI MSS at the back of the antenna structure. The proposed NZRI MSS-loaded CPW-fed (Co-Planar Waveguide) fo...

Extremely small aperture radial line slot antennas (RLSAs) are analyzed by method of moments. At first, the analysis model of cylindrical waveguide in terms of rectangular cavity modes is confirmed for a RLSA with a spiral slot arrangement. The overall VSWR as well as rotational symmetry of the actual structure of RLSAs is predicted for the first time and is confirmed experimentally. Secondly, ...

A Dielectric Resonator loaded Substrate integrated waveguide cavity backed slot antenna (SIDRA) is proposed for two slot polarizations and orientation. A SIW-fed cylindrical DRA using rectangular slot is used for obtaining bandwidth of about 5% at 6.15 GHz. For enhancing bandwidth, a plus shaped slot with bandwidth of about 8.80% and gain of 3.7 dB is proposed. The proposed antenna represents S...

Compact Circularly Polarized Slot-Ring Antenna and Microstrip Bandpass Filter Using Triangular Open-Loop Resonators. (December 2006) Muhammad Fahad Farooqui, B.E., NED University Chair of Advisory Committee: Dr. Kai Chang In this thesis two different research topics are undertaken, both in the area of compact RF/microwave circuits design. The first topic involves the design of a compact circula...