What’s the difference between FMCW and CW radars?

The radar principle used is FMCW (Frequency Modulated Continuous Wave). The FMCW-radar transmits a high frequency signal whose frequency increases linearly during the measurement phase (called the frequency sweep) . The signal is emitted, reflected from the measuring surface and received with a time delay, t.

If CW Doppler Radar uses the Frequency Modulation, then that Radar is called FMCW Doppler Radar or simply, FMCW Radar . It is also called Continuous Wave Frequency Modulated Radar or CWFM Radar. It measures not only the speed of the target but also the distance of the target from the Radar.

Radar systems measure the time of flight from when a transmitted signal leaves the radar, hits a reflecting target and returns to the radar .