Processing-based tuner gain correction in a wideband multi-channel receiver

Abstract

Modern radar systems often capitalize on advanced radio frequency components in the receiver front end to include wideband tuners and amplifiers, highly stable local oscillators, and high-speed analog-to-digital converters. Yet, technology demonstrators often emphasize either the hardware or the processing algorithm rather than the end-to-end system. This paper presents the hardware characterization of tuner-gain mismatch in a wideband multi-channel array and the subsequent signal processing calibration model. The gain model is empirically found to follow a T-distribution and is used to balance the amplitude across the tuners as part of the processing for time-frequency-beamforming. Phase is also shown to be the critical factor to completely correcting phase mismatch. Here, we present details of the wideband receiver front-end and the signal processing backend.