Design and Measurement of a Reconfigurable Transmitarray Antenna With Compact Varactor-Based Phase Shifters

A reconfigurable transmitarray antenna (RTA) with 360 degrees continuous transmission phase controlling capability is designed and experimentally validated in this letter. The proposed RTA element is based on the receiver-transmitter structure. A compact varactor-based analog phase shifter using a coupled-line structure is utilized to provide a 0 degrees to 180 degrees continuous transmission phase. Two PIN diodes integrated on the active transmitter patch are alternatively turned on to generate an additional 180 degrees phase shift using the current reversal mechanism. The element simulations show a magnitude insertion loss varying from 0.95 to 1.35 dB at 5.6 GHz, and a wide 3-dB transmission bandwidth of 16.7%. A prototype composed of 16 x 16 elements is fabricated and measured. The measured broadside gain is 23.7 dBi at the design frequency with a 3-dB gain bandwidth of 15.7%. Good two-dimensional (2-D) beam steering capability within +/- 60 degrees is also experimentally verified.