A Reconfigurable Microstrip Antenna With Radiation Pattern Selectivity and Polarization Diversity

A novel reconfigurable microstrip antenna with radiation pattern selectivity and polarization diversity is presented in this letter. A four-way power divider made by three Wilkinson power dividers and interconnected with switches (currently copper strips for proof of concept) is designed to feed this antenna. By controlling the states of the switches, the antenna characteristics can be changed into two modes. When the four rectangular radiating patches are excited by four sources with equal amplitude and phase, a metamaterial antenna with conical beam and linear polarization (LP) is achieved, while four sources with equal amplitude but 90^° phase difference for each adjacent output leads to a wideband antenna with broadside beam and circular polarization (CP). This single-port antenna is useful for terrestrial land-mobile or other wireless applications.