Beam Nulling Designs of Reflectarray Antenna Using Alternating Projection Method

Abstract

This letter presents beam nulling designs of reflec-tarray antenna (RA). By using alternating projection method (APM), one or more nulls with certain widths can be formed in analog phase RA. In the first case, a single narrow null has a depth of -48dB and has nearly no effect on the main beam. In more complex cases, a wide null or three nulls have a depth of about -40dB, resulting in 0.49dB gain decrease and 7.04dB sidelobe level (SLL) increase. Quantized phase RA can also form a null base on the analog phase distribution. The minimum quantization bits are related to the aperture size.