Impact of even and odd order non-linearity on PMCW radars

We assess the impact of non-linearity on binary phase-modulated continuous-wave (PMCW) radars. Binary sequences with excellent auto-correlation properties can be found for PMCW radars. They feature very low range sidelobes, which is a mandatory requirement in realistic automotive scenarios to avoid strong targets masking weaker ones. It turns out that non-linearity in the TX and RX chain can degrade the autocorrelation properties of binary sequences and create range sidelobe regrowth. The pattern of the regrowth is specific for each family of binary sequence. We provide a detailed analytical model for the non-linearity in PMCW radars and provide simulation results and real measurements with a 79GHz radar validating our analysis and simulations.