A Wideband Dual-Polarized 1-bit Unit Cell for Reconfigurable Intelligent Surface Applications

In this paper, a wideband 1-bit dual-polarized unit cell has been presented at Ku-band. It comprises three substrates and four metallic layers. The proposed structure uses polarization conversion technique, and out of phase characteristic of electric field in patch dominant mode to get two phase states. Using this characteristic provides the proposed structure with considerable bandwidth and accurate phase difference between two states. Two PIN diodes are used as switches for two phase states. Activating one diode for each state results in the conversion of x-polarized to y-polarized (and vice versa) incident wave with a 180 ° phase difference between the two states. Notably, only one control voltage suffices for both diodes, simplifying the design of the control system. The proposed structure has been simulated using CST software. Numerical results show good matching and 180 ° ±2 ° phase difference between two states from 11.2 GHz -14.2 GHz with 25 % relative bandwidth. The proposed structure can be used for different beamforming, beam steering and RIS applications.