Tracking dynamics of retrodirective vehicle RADAR with track hold ability

This paper considers the tracking dynamics of a retrodirective RADAR when applied to a vehicular scenario. The advantages of such a RADAR system are discussed in comparison to a conventional RADAR. More specifically, a “track hold” function is presented for a retrodirective RADAR, which is shown, for typical vehicle turning rates, to be able to maintain the retransmitted beam towards the target during dropouts in the reflected signal. These dropouts could be caused by effects such as variations of target radar cross section with angle of incidence. The “track hold” feature prevents the need for a reacquisition of the target after the dropout and also provides the possibility of using the RADAR to reliably transmit data to the target. The ability to provide a reliable retransmitted beam, even in the absence of a target reflected signal, is a significant improvement compared to traditional mixer based retrodirective antennas, which are unable to maintain the retransmitted signal in the absence of a received signal.