Wideband ?45? polarization reconfigurable aperture-fed patch antenna

This paper introduces a wideband aperture-fed patch antenna with ± 45° reconfigurable polarizations. A new method is proposed to achieve the switchable ± 45° polarizations by designing a reconfigurable feeding aperture for a square radiating patch. To realize this, we introduce four PIN diodes as RF switches connected between a cross feeding aperture such that the orthogonal directions of the rectangular aperture can be controllable. As the result, ± 45° polarizations can be reconfigured since the polarization is determined by the direction of the feeding aperture. In order to widen the bandwidth of a single patch antenna, we introduce a parasitic patch above the main radiating patch to bring an additional resonance. The bandwidth of the double-patch structure can reach 21% which is much wider than that of a single patch. In addition, the antenna has a stable gain across the operating bandwidth with the peak gain of 9.6 dBi. Good broadside radiation patterns are obtained with the 3-dB beamwidth of 56 degree. The antenna is suitable for applications requiring wideband and polarization reconfigurable characteristics.