Reconfigurable Phased-Array Antenna Using Continuously Tunable Substrate Integrated Waveguide Phase Shifter

Abstract

A low-cost $1 \times 4$ phased array incorporating continuously tunable substrate integrated waveguide (SIW) phase shifters is presented in this paper. Through seamless integration between antenna elements, phase shifters, and an SIW feeding network, the proposed phased array is assembled in a multilayered monolithic structure. To obtain a wide phase variation range, the electronically controllable phase shifter is constructed by introducing varactor diodes into a reflection-type architecture, which can also offer a simple solution to constitute the biasing circuit of the diodes. Due to the merits of adequate bandwidth and good radiation performance, an aperture-coupled patch antenna with multi-resonance characteristic is selected as the array element. Accordingly, a prototype of the proposed phased array was fabricated by applying standard printed circuit board (PCB) facilities. The measured results demonstrate that a continuous beam scanning range from −45° to 45° covering the whole operating band of 5.09–5.98 GHz is obtained. Meanwhile, a gain of up to 11 dBi and an impedance bandwidth of 16.1% are achieved. Owing to the features of continuous wide-angle steerable beam, easy fabrication, and integration, the proposed phased-array antenna is attractive for 5G Wi-Fi applications.