A Liquid-Metal Monopole Array With Tunable Frequency, Gain, and Beam Steering

A reconfigurable five-element Yagi-Uda monopole array is presented that utilizes pressure-driven liquid-metal elements. There is one centrally located driven element and six parasitic elements in the array, all of which utilize liquid metal so that their physical lengths can be varied. This allows the array to tune to different operational frequencies, vary the number of director elements, and change parasitic elements from reflectors to directors, and vice versa. The measured results show beam steering along a single axis and 1.33 dB of gain tuning at 2.4 and 3.87 GHz.