A Frequency-Reconfigurable Coaxial Liquid Metal Yagi-Uda Antenna with Arbitrary Directivity

This paper introduces a reconfigurable Yagi-Uda antenna using liquid metal eutechtic gallium and indium (EGaIn). The antenna consists of three coaxial circular capillaries inserted with electrolyte and certain amount of liquid metal according to their different functions. Arbitrary intended directions in 2D-plane can be realized by changing the position of EGaIn in each capillary electrochemically. The resonant frequency is also adjustable by altering the location of the feed element. The results of HFSS simulation show that the antenna has resonant frequencies of 1.69 GHz and 2.03 GHz with high gain in the intended directions.