An Integrated Wide-Angle Scanning Planar Phased Array Based on Pattern Reconfigurable Antenna

This article demonstrates an integrated wide-angle scanning planar phased array based on pattern reconfigurable antennas (PRAs). The PRA unit consists of four rotationally symmetrical elements with a dimension less than $0.41~\lambda \times 0.41~\lambda $ . By exciting different elements, the beam of the unit switches between four modes and has a 3 dB coverage of ±77°, which helps the antenna array achieve an expanded scanning range. The reconfigurable principle and bandwidth enhancement method of the compact antenna unit are analyzed; the radiation efficiency and the performances of the array are also discussed. The whole system of the phased array is integrated on a multilayer hybrid PCB board, which includes a $4\times 4$ reconfigurable antenna array, TR modules, 4-channel RF chips, a beam control circuit, and a power management circuit. The measured return loss of the antenna unit is less than −10 dB in the frequency range of 27–30 GHz, and the scanning range is from −68° to 68° with a maximum gain of 16.4 dBi. The gain fluctuation of the array in beam scanning is less than 2 dB, and the scanning range of −3 dB covers ±80°.