Analysis of a gap-coupled stacked annular ring microstrip antenna

Abstract

A theoretical analysis of a gap-coupled stacked annular ringmicrostrip antenna with superstrate is performed in order to obtain wider bandwidth operation. The effects of air gap, superstrate thickness and feedingp oint location on the antenna performance are analyzed in TM11 mode usingequiv alent circuit concept. It is noted that the proposed antenna is very sensitive to the feedingp oint location in TM11 mode while annular ringmicrostrip patch antenna is independent of feed point in that mode. The optimized proposed antenna shows an impedance bandwidth of 13.96% whereas the antenna without air-gap has 8.75% bandwidth and without superstrate it has bandwidth of 10.89%. The theoretical results are compared with simulated and experimental results.