A tunable low-pass filter using a liquid-metal reconfigurable periodic defected ground structure

Abstract

A new type of tunable low-pass filter is demonstrated that uses liquid metal to reconfigure a defected ground structure (DGS). By filling in different DGS lattices with Galinstan liquid metal, the tunable low-pass filter provides tuning of up to eight cutoff frequencies. Measurements of four of the cutoff frequencies show a 62% tuning range while maintaining a stopband of more than 5 GHz.