A New Quadri-Polarization Reconfigurable Circular Patch Antenna

A new probe-fed patch antenna with polarization reconfiguration is presented in this paper. The antenna is composed of a circular radiating patch and a switchable feed network. By controlling the operating states of four pairs of PIN diodes in the feed network, the feed point of the circular patch can be switched. Therefore, a reconfiguration between four linear polarization directions at a 45° interval (22.5°, 67.5°, 112.5°, and 157.5°) can be realized. All the different polarization states own similar matching and radiation characteristics. Simulated and measured results indicate that the antenna can achieve reconfigurable quadri-polarization diversity features with an invariable operating frequency and excellent radiation performance, which are very attractive for wireless communications. In addition, the proposed design can offer more reconfigurable linear polarization directions by adding more switchable paths in the feed network.