In this paper, the effect of shorting wall length on the circular polarization of shorted microstrip patch antenna is examined. The theoretical analysis is based on the High Frequency Software Simulator (HFSSR). A designed antenna for the GPS application at the civilian GPS frequency (1.575 GHz) has been fabricated and measured. The measured data for the fabricated antenna is taken by 8719 ES vector network analyzer. Results of the designed antenna show good circularly polarized with a reduction in its size by 24.6 % from the conventional rectangular microstrip patch antenna. Simulated and measured results for the proposed antenna are presented.

This paper introduces a new application of genetic algorithm (GA) in dynamic sector synthesis of antenna array for mobile base transceiver station (BTS). The basic objective is to have narrow beam widths in heavy handoff areas and wider beam widths in areas with low traffic density. By predefining the beam widths and thus the beams of each sector, optimal sectoring can be achieved using GA at different time of the day as traffic changes. The proposed algorithm consists of the simple GA with new adaptive mutation mechanism. When compared with simple GA, the proposed algorithm shows faster convergence. The results obtained are more stable and having higher fitness.

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