A detailed study and implementation of an RPC for LFM-CW radar

Reflected power cancellers (RPC) alleviate the problem of low isolation in lineal frequency modulated continuous wave (LFM-CW) radars. Several prototypes have already been published, but there is a lack of a unified analysis of this system. We have carried out an in-depth study of the RPC performance by using the RPC closed-loop frequency response. Simulations and measurements of an RPC prototype for an X-Band LFM-CW radar have been performed. In this paper we present the main conclusions of the study, such as limitations of the vector modulator, phase shift restrictions to ensure stability and delay equalization to cancel phase noise