A two-layer beam-steering array antenna with 4 × 4 modified Butler matrix fed network for switched beam application

摘要

This paper presents a novel two layers beam-steering array antenna fed by a4 × 4 modified Butler matrix. Each of the radiation elements have been replacedby a collection of 2 × 2 circularly polarized (CP) square patches, whichjoined together by a modified sequentially rotated feed network. The antennaarray consists of 2 × 5 CP square patches, which connected to four ringsequential rotation and fed by butler matrix. The proposed Butler matrixwhich plays a role as beam-steering feed network consists of four novel 90 circularpatch couplers and two 45 half circular patch phase shifter. Altogether,using of a 2 × 5 phased array antenna and a modified Butler matrix cause toempower array antenna for covering frequency range between 4.67 to6.09GHz, the maximum gain of 14.98 dB and 3-dB axial ratio bandwidth of1.2GHz (4.9～6.1GHz) is attained.