A bistatic radar, which allows to process the target velocity information, must synchronize the phase and the frequency of the transmitted carrier to demodulate coherently the radar echoes. The paper presents a PLL system which looks on the carrier of the radar signal received when the transmitter antenna illuminates directly the receiver. The PLL includes a digital circuit to hold the VCO control voltage when the direct signal is not avalaible. Also, it's shown the effects of phase and frequency errors in the target velocity detector and how these errors are affected by the synchronizer and the transmitter.