A Microwave Subsystem (MS) Capable of Realizing Functional Change with the Aid of 2D-shaped Liquid Metal (LM)

This paper presents the first microwave subsystem (MS) capable of changing its function, in this case between resonator and antenna, using liquid metal (LM). This is achieved by filling/emptying fluidic channels with Gallium-based LM and forming LM into different 2D shapes. The manufactured prototype of the proposed MS performs as a slot antenna, when the fluidic channels are empty of LM. On the other hand, it operates in resonator mode, when the fluidic channels are filled with LM. We also connected two MSs along with a microstrip resonator to realize functional change between complex functions, i.e., antenna and filter. The proposed connection of MSs can act as a filter when the fluidic channels are filled with LM or as an antenna when LM is withdrawn from the fluidic channels. When operating in the antenna mode the proposed connection of MSs provides a measured peak realized gain of 7.23 dBi and a simulated total efficiency of 84%. When operating in the filter mode the connection of MSs provides a band-pass response and exhibits a minimum insertion loss of 1.9 dB, within the passband. The filters 10 dB return loss bandwidth, of 340 MHz, ranges from 2.28 GHz to 2.62 GHz.