Characterization of Variable Phase Resolution and Cross-Channel Amplitude Imbalance Effects in 100GHz Active Beam-Steering Phased Array

Paper in proceeding, 2026

This paper characterizes how different-resolution phase control and amplitude imbalance affect scanning performance in W-band active phased array antennas. The case study is a ridge-gap-waveguide array antenna with 0.56 wavelengths spacing at 94 GHz and a multi-channel active module with integrated phase shifters (5-bit) and power amplifiers operating at 92-96 GHz. The analysis incorporates measured frontend performance and the simulated antenna S-parameters and embedded-element patterns. Using these results, we evaluate 1to 5-bit phase control and the amplitude imbalance across active channels. The active array antenna achieves grating-lobe-free beamsteering within plus-minus 50 degrees; main beam scan loss does not exceed 1.3 dB. A rise in the average side-lobe level and quantization lobes due to the phase quantization and amplitude imbalance is demonstrated for the practical front-end. From these results, we formulate strategies for performance improvement. The framework is generalized to other millimeter-wave arrays with electronic beam-steering.