A tunable metamaterial-based linear-to-circular polarization converter regulated solid state plasma in S-band

As the most widely used band in wireless communication systems, S-band is often used in many military and civil fields. In this paper, with the aid of the reconfigurability realized by the solid state plasma (SSP), a tunable metamaterial-based polarization converter is proposed and theoretically investigated. Through the premeditated excitation of the SSP resonators in the specific region, the linear-to-circular polarization conversions with two different operating states can be realized and switched to each other. The numerical results show that the polarization converter can obtain circularly polarized waves in two separate bands (2.15–2.63 GHz and 3.18–3.71 GHz) when our design is in State I, and the dual operating bands expands and merges into a consecutive ultra-wideband range (2.04–3.67 GHz) when our design is switched to State II. The total tunable working range of the presented polarization converter can essentially cover the whole S-band and the phenomenon of the isolation and fusion of the operating band possesses great potential application value in the fields of radar radomes, polarization separation, electromagnetic shielding, and so on. (paper)