Analysis of frequency reconfigurable microstrip patch antenna with unidirectional radiation pattern for IRNSS band

This paper presents the numerical approach for dual-band frequency reconfigurable microstrip antenna. The proposed antenna is the combination of rectangular patch and slot, which is separated by a narrow gap. Three RF PIN diodes are brought together to fill the gap and achieve dual-band frequency reconfigurability. It resonates at 1.1753 GHz (1.16 GHz-1.19 GHz) and 2.4895 GHz (2.47 GHz-2.51 GHz) with maximum gain of 1.20 dBi and 8.515 dBi, respectively. The antenna provides stable unidirectional radiation patterns at both the resonant frequencies during frequency reconfiguration operation. The proposed analytical model offers physical insight into the working of this antenna and can also be used to predict frequency switching before full-wave analysis is performed. The prototype is fabricated and compared with simulated results and is suitable for wireless communication systems especially for Indian Regional Navigation Satellite System (IRNSS) receiver.