Design of Frequency-Scanned Multi-Polarization Antenna Based on Polarization Rotator

A multi-polarization antenna consists of a bi-directional planar antenna and a polarization rotator array is proposed in this paper. Two orthogonal components of the radiated wave with the same magnitude are generated by the combined action of the planar antenna and the rotator. The distance between these two structures can adjust the phase difference between two orthogonal components ranging from -90° to 180° and monotonously changing with the frequency. The simulated results indicate that left-handed circularly-polarized (LHCP), right-handed circularly-polarized (RHCP) and two diagonal linearly-polarized (LP) waves are obtained at four different frequencies. Furthermore, these four states of polarized patterns can be switched by scanning the frequency. The proposed antenna with a fixed structure and a single feeding port can potentially be used in some applications requiring multiple polarization patterns.