A Ka-band reflectarray consists of patch cells with metallic vias is investigated in this paper. The reflectarray consists of 29 × 29 patch cells and covering an area of 14.5 cm × 14.5 cm. The unit patch cell is composed of a square metallic patch supported with multiple position variable metallic vias beneath it, and the back surface of the thin substrate is conducting ground plane. Varying the position of the vias can lead to 360° phase shift. The reflectarray is offset fed by linearly polarized pyramidal horn antenna. Two commercial electromagnetic simulation softwares of CST and HFSS were used for simulating the phase shift of cells and the antenna performance. The measured and simulated 3dB beamwidth is 6°, the peak gain of 31 dB is predicted at 30 GHz. The reflectarray can cover from 27.5 GHz to 31.75 GHz, or 14 % bandwidth, and the aperture efficiency of 47.5 % at 30 GHz with better side lobe level and flat gain were achieved, which is better than the reflectarray with size variable patch cells. |
