FMCW radar system with additional phase evaluation for high accuracy range detection

A radar based approach of range detection depends mainly on the utilized radar principle which allows either high accuracy or high unambiguous ranges. For the most widely used FMCW radar the entire distance is not restricted in the meter range whereas the achievable accuracy directly depends on the bandwidth. An improvement is only possible if system parameters are changed or a smart signal processing is applied. In this paper an approach is described which extends the FMCW radar with an additional phase evaluation to facilitate also high accuracy using low-cost radar components and none intensive processing methods. Therefore requirements for frequency and phase evaluation must be kept which are investigated and solved using special algorithms. The performance of these proceedings is confirmed with measurements using a developed radio frequency circuit for the K-band. Moreover the possibility to combine the frequency and phase information for range detection is described and also validated by measurements.