A Wide-Angle Beam Scanning Reflectarray Antenna with Four Focuses Design and Staggered Arrangement of Elements

This paper presents a wide-angle beam scanning reflectarray antenna which is working at Ka-band. The proposed reflectarray is consist of a reflecting surface with two-layer subwavelength square patch elements which are in staggered arrangement and a movable dual-mode conical horn. Four focuses design is applied to compensate phase error caused by rotating the feed horn. The simulation results demonstrate that the variation of gain is 1.4 dB, the side lobe level is lower than -16.3 dB and aperture efficiency is larger than 59.6% within ±30° scanning angles at typical frequency of 35 GHz. The designed antenna has the characteristics of stable gain, high aperture efficiency and lower side lobe level, and can be applied to millimeter wave imaging system.