A Study of Phase Quantization Effects for Reconfigurable Reflectarray Antennas

A systematic study of phase quantization effects on the beam scanning performance of reconfigurable reflectarray antennas (RRAs) is presented. The spatial feeding scheme of RRA introduces an intrinsic pseudorandom distribution of the phase quantization error, which effectively eliminates the grating lobes and high parasitic sidelobes. It is observed that the phase quantization does not affect the half-power beamwidth, but increases sidelobe levels. The gain loss due to phase quantization is computed for different quantization bit numbers and different scan angles, and the maximum aperture efficiencies are derived accordingly. Finally, the measured results of two 1-bit RRAs with 10 × 10 and 40 × 40 elements validate these observations.