A single‐layer filtering patch antenna array with simple differential feeding network

Abstract

This paper proposes a single‐layer filtering patch antenna array with simple differential feeding network. It is composed of a simple microstrip‐slot‐microstrip differential feeding network, four patch elements, two open‐ended lines and two U‐slots. Two gain nulls in the lower band and the upper band can be generated by introducing open‐ended microstrip lines and U‐shaped slots, respectively. Therefore, the selectivity of the gain curve is significantly improved. The proposed antenna array has an optimized dimension of 80 × 80 × 0.8 mm3 and a peak gain of 11.2 dBi. The measured impedance bandwidth (|Sdd11| < −10 dB) is 4.7% ranging from 5.01 GHz to 5.25 GHz. Additionally, the proposed antenna array also achieves common‐mode suppression in the whole band.