A Wideband Frequency- and Polarization-Reconfigurable Liquid Metal-Based Spiral Antenna

This letter work develops a liquid metal-based spiral antenna for frequency reconfiguration over an ultrawide band and polarization reconfiguration at a partial operating band. Dual-layer polymethylmethacrylate microfluidic is glued on the dielectric substrate to provide channels for liquid metal flow. The syringe could smoothly control the liquid metal to change the lengths of the spiral antenna arms and result in effective frequency reconfiguration. Moreover, polarization reconfiguration between left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) is achieved by redistributing the liquid metal from the upper layer microfluidic channels to the lower layer microfluidic channels. Experimental results demonstrate that the proposed antenna supports continuous frequency reconfiguration from 0.6 to 13.5 GHz and realizes polarization reconfiguration between RHCP and LHCP from 1 to 2.5 GHz. The presented design enabled robust communications over a broad frequency spectrum.