Impact of Phase-Shift Beamforming on Wideband Communications Systems

Electronically steered arrays (ESAs) are essential to directional mesh networks in military communications. However, their current state-of-the-art implementation uses phase-shift beamforming, which is a narrow band approximation of time delays resulting in beam squint for wideband communications. We show OQPSK bit-error-rate simulation results demonstrating the impact of beam squint and the effectiveness of adaptive equalization as a function of array dimension and bandwidth. We also present a hybrid analog-digital beamforming architecture that can mitigate beam squint for a relatively small increase in cost.