A Compact and Fast $1 \times 4$ Continuously Steerable Endfire Phased-Array Antenna Based on Liquid Crystal

This paper presents a planar end-fire Yagi-Uda antenna phased array fed by a corporate network. The phase of each radiating element is controlled by a loaded line phase shifter based on liquid crystal (LC) technology. The phase shifters are meandered to minimize the dimension of the array and are measured to provide maximum differential phase shift of 400 with an figure-of-merit (FoM) of 54 /dB at 28.4 GHz. Each phase shifter is tuned individually by applying bias voltage through high impedance chromium (Cr) line together with DC blocks. The array is designed for full range scanning in E-plane with > 360 phase shifters. Measurements show it can be steered from 40 to 40 by applying DC bias in the range of 0V to 5 V, and from 50 to 60 with degraded patterns. The maximum gain of the phased array antennas is measured to be 6.0 dBi. The array beam is able to be fast steered within approximately 1 s.