Wideband Transmissive Polarization Rotator With In-Band Notches Enabling Multiband Operation

Abstract

A low-profile and wideband transmissive polarization rotator is proposed in this article. The wideband performance is accomplished by utilizing a curved bowtie resonator. The proposed wideband design exhibits a simulated bandwidth of 129.07% for at least 90% cross-transmission coefficient. The operating bandwidth is from 22.8 GHz to 105.8 GHz and the structure thickness is $0.082~\lambda _{\mathrm {max}}$ , where $\lambda _{\mathrm {max}}$ is the free-space wavelength at the lowest operating frequency. A comparison with previously reported wideband polarization rotator designs is performed to highlight the notability of the proposed design regarding the wideband performance and structure thickness. In addition, in-band notches are utilized within the wide operating band to accomplish a transmissive polarization rotator with multiple operating bands. Single and double notches are employed to achieve polarization rotator designs with dual- and tri-band of operation, respectively. Moreover, the proposed multiband technique enables bandwidth adjustment. The prototype is fabricated and experimentally studied and is found to be highly correlated to the numerical estimation.

Keywords

• Multiband
• polarization conversion
• transmissive polarization rotator
• wideband