Filtering dual‐patch antenna with flat gain response using F‐shaped feeding structure

Abstract

AbstractA novel wideband filtering dual‐patch antenna with a flat gain response is presented in this letter. This filtering antenna mainly consists of two parts: two patches and an F‐shaped feeding structure. The upper and lower patches are fed by two different horizontally placed narrow strips from the F‐shaped structure. Two patch modes are simultaneously excited within the passband, yielding a 29.3% bandwidth with a very flat gain response and a stable radiation pattern. Furthermore, a pair of radiation nulls are generated symmetrically at the two sides of the passband owing to the mutual coupling between two patches. As a result, a filtering antenna without any extra filtering circuit is obtained which achieves a realized gain of 10 dBi within the passband and an out‐of‐band suppression level of 15 dB in the lower stopband and 20 dB in the upper stopband. Compared to the traditional patch antennas, this proposed filtering antenna demonstrates a very flat gain response, a sharp passband skirt, and a good selectivity, which is well designed and very suitable for high band cellular communication (2.0‐2.7 GHz).