One of the most limiting impairments of an FMCW radar system in terms of range precision and detection sensitivity is the phase noise (PN) contained in the transmit signal. To fully understand the influence of PN on the radar measurement, a fast and accurate PN simulation environment, including state-of-the-art radar signal processing algorithms for signal evaluation, was implemented [1]. The simulator directly calculates the baseband signal and thereby omits computationally expensive RF rates. This results in very fast simulations, since the baseband bandwidths are typically in the low MHz range.

The thereby acquired knowledge was used to develop a PN monitoring function for high resolution radar sensors [2]. These high resolution radar systems are able to precisely locate and identify objects in their field of view. To provide the therefore required number of transmit and receive channels, multiple radar MMICs are connected, i.e. cascaded. The developed monitoring function estimates the mean PN power spectral density (PSD) of two radar MMICs during operation. This estimation result can subsequently be used to detect if the MMICs generate PN out of specification. Different to most of the existing work, this method uses an application relevant FMCW signal instead of a continuous wave signal. Since PN monitoring functions are indispensable in terms of FuSa for ADAS and future AD, the method was patented, and further publications are in progress.