Some investigations on annular ring microstrip antenna

Abstract

In the present paper the design considerations for the annular ring microstrip antenna is considered and consequently various parameters such as input impedance, VSWR, return loss, radiation pattern have been theoretically investigated as a function of frequency for different feed locations with a view to optimize the feed location for proper matching and radiations. It has been observed that resonance occurs at 3.285 GHz. The antenna behaves as RL network below resonance and as RC network above resonance. Antenna shows perfect matching at 3.35 cm. feed location from the center. The percentage bandwidth is found decreasing with increasing b/a.