Analysis of Time-Interleaved ADC Offset and Gain Mismatch Errors in PMCW Radar

Abstract

Phase-Modulated Continuous Wave (PMCW) Radar can enable future autonomous driving thanks to its robustness against interference and flexibility in the digital domain. However, there are stringent requirements for the Analog- Digital Converter (ADC), in terms of speed and linearity, which are due to the needed radar range and Doppler resolution. Time-interleaving is used to attain the required signal bandwidth while achieving a high effective number of bits (ENOB) by compensating mismatch errors between different time-interleaving channels. This paper analyzes the dominant time-interleaving errors: offset and gain. The paper demonstrates how they impact PMCW radar performance by creating ghost targets and decreasing signal-to-noise ratio (SNR).