الفهرس 
chapter 1Only 14 pages are availabe for public view
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Abstract
Retrodirective antenna arrays, when illuminated by an interrogator signal, transmit a signal back towards the interrogator in the same direction as the
incoming signal, without any prior knowledge of the source direction or digital signal processing. Retrodirective antennas are classified into two basic architectures; Van Atta arrays and phase conjugating arrays. A Two dimensional passive Van Atta retrodirective array is proposed using dual port dual polarized microstrip square patch antenna at a frequency of 2 GHz. The dual polarized microstrip antenna is designed using the aperture coupled feeding technique. A parametric analysis is performed till reaching the optimum design which yields 7.4 dB peak gain, 140º half power beam width. Full 3D EM simulation of the designed antenna array is performed. The Monostatic Radar Cross Section for the proposed structure is presented. The double-substrate structure used enhanced the bandwidth of the antenna element by 41% than previous references. The proposed array configuration achieved excellent cross-polarized monostatic RCS within ±55º compared to other recent publications. In addition, the cross-polarized level of the array is easily distinguished from that of the flat plate by greater than 30 dB. In addition, a novel active 2x2 Van Atta array is proposed based on transistor-based LNA design and RFIC-based design. Design procedures are explained starting from initial simulations up to final layouts. The use of amplifiers as in this array architecture provides additional benefit of increasing the cross-polarization level of the array. Accordingly, the retrodirective component can be easily distinguished from the other field components.