Polarization agile self‐oscillating active integrated antenna for spatial modulation wireless communications

This article proposes a new design concept of active integrated array antennas having oscillation and modulation functions for spatial modulation wireless communication systems. Several configurations of the active integrated array antennas are proposed and discussed. The proposed active integrated antennas provide polarization modulated radio waves with a simple structure. A polarization switchable ring‐slot active integrated antenna employing Gunn oscillators is designed and experimentally demonstrated as an example of the proposed concept. The prototype active integrated antenna successfully switched its polarization angle between ±45°. The proposed active integrated antenna concept was found to be feasible.