Frequency-switchable half-mode substrate-integrated waveguide antenna injecting eutectic gallium indium (EGaIn) liquid metal alloy

A frequency-switchable half-mode substrate-integrated waveguide antenna is proposed. The resonant frequency of the proposed antenna is switched by injecting liquid metal (eutectic gallium indium; EGaIn) into a single vertical fluidic hole. The position and dimensions of the fluidic hole are chosen in order to maximize the tuning ratio and peak gain. The radiation performance is demonstrated through full-wave simulation and measurement. The resonant frequency is successfully switched from 2.33 to 3.35 GHz by injecting EGaIn into the vertical fluidic hole while maintaining the peak gain higher than 6 dBi.