Broadband proximity fed modified rectangular microstrip antenna

The broadband microstrip antenna is realized by cutting the slot of different shapes like U-slot, V-slot and pair of rectangular slots inside the patch. The slot is said to introduce a mode near the fundamental resonance frequency of the patch and realizes broadband response. By using thicker substrates in excess of 0.08λ0, the bandwidth of slot cut microstrip antenna is increased by feeding the patch using the simpler proximity feeding technique. In this paper, a half U-slot and rectangular slots cut proximity fed broadband rectangular microstrip antenna is proposed. The analysis to study the effects of slot on the broadband response of slot cut patch is presented. Through the analysis it was observed that the slot modifies the resonance frequencies of higher order modes of the patch and yields broadband response. The bandwidth of more than 550 MHz (>; 45%) is obtained. The antenna gives broadside radiation pattern with a gain more than 5 dBi over the operating bandwidth.