Design and Fabrication of a 220GHz Circularly Polarized Dielectric Reflectarray

A broadband circularly polarized (CP) dielectric reflectarray operating at 220 GHz is proposed in this paper, which consists of 11 x 11 elliptical cylindrical dielectric cells (dielectric constant 3.3) and a metal ground. The cells of this array placed diagonally at 45 degrees along the square floor. The linear polarized horn is chosen as a feed and then the CP waves are reflected. Amplitude and phase characteristics can be controlled by changing the height of the cell, and then the optimized cell can be built a reflectarray so that the reflected beam can be emitted in any direction. Simulation results show that the proposed reflectarray achieves the maximum gain of 19.1 dBi operating and 1 dB gain bandwidth of 14.2% at 220GHz. A broad 3 dB axial ratio bandwidth can be achieved 16.5% In view of the need for processing accuracy in the sub-THz band, the high-precision 3D printing technology with accuracy of 10 gm is used for the processing of the object.