A Miniature Reconfigurable Circularly Polarized Antenna Using Liquid Microswitches

A frequency and polarization reconfigurable antenna based on electrowetting liquid metal microswitches is presented. The microswitches consist of electrostatically actuated mercury droplets that selectively connect solid metal traces. This mechanism is designed into a single-feed patch antenna configurable between two communication bands and the GPS band with different circular polarizations. The antenna topology is based on a corner truncated square patch with switched sets of extensions to achieve resonant frequency and axial ratio control. Measurements of manually reconfigured prototypes demonstrate frequency and polarization configurability.