Coherent Virtual Aperture Calibration in Uncoupled MIMO Radar Networks

Abstract:
Uncoupled radar networks offer the advantage of enabling large virtual apertures without the need for a costly RF link connecting individual radar sensors. To fully harness the potential of the large virtual aperture of such a network, it is imperative to address hardware impairments, including gain and phase imbalances among individual virtual channels. The distinctive signal structure inherent in uncoupled MIMO radar networks introduces novel challenges in the estimation of phase imbalances. This paper describes a sub-aperturebased calibration method designed to address these challenges effectively, facilitating the calibration of virtual apertures within uncoupled MIMO radar networks. The presented method is validated by measurements with an uncoupled MIMO radar network consisting of 2 sensors using CS-FMCW and operating at 76GHz, realizing a virtual aperture with a total of 768 virtual channels.