Monopulse angular evaluation for a MIMO millimetre-wave radar with a sparse aperture configuration

This article reports on the principles of evaluation and the experimental results obtained by a mm-wave FMCW MIMO radar system with a sparse aperture con- figuration and an additional receive antenna for the application of the phase monopulse principle. While ranging information is obtained by standard FMCW techniques the 2D system capability stems from the generated virtual array. The azimuth information is evaluated by exploiting the characteristics of the signal covariance matrix. Supplementary information about elevation can be obtained from the originating monopulse virtual array. A new evaluation method which can handle the occurring phase ambiguities and allows to correct for the system-inherent coupling between elevation and azimuth, is presented. Laboratory experiments confirm suitability and accuracy of the approach.