Mitigation methods of sawtooth modulations effect on FMCW radar INDERA MX-4

LFM sawtooth modulation technique on FMCW radar is used in a relatively large radar range and with a negligible influence of Doppler frequency. Despite its advantages, inaccurate timing of transmitted signals and beat signal acquisition process on FMCW radar by using sawtooth modulations give effect on reducing SNR and capability of target detection. In this study, we developed methods to synchronize beat signal using overshoot detection and data shifting to reduce the effect of inaccurate hardware timing in the LFM sawtooth. The overshoot is mainly caused by abrupt changes at the end of the sawtooth, commonly called No-Dwell. This developed method has been tested on INDERA MX-4 coastal radar. The method demonstrated improved radar dynamic range of 20 dB and a reduced noise floor from -18 dBm to -45 dBm.