Which type of Doppler radar sends a steady signal instead of pulses?

Continuous-wave radar sends a steady radio signal instead of transmitting separate pulses.

A continuous-wave, or CW, radar radiates electromagnetic energy continuously and listens for reflections at the same time. Motion changes the frequency of the returned signal through the Doppler effect, allowing the radar to determine a target’s range rate—its speed toward or away from the radar.

This differs from pulse radar, which alternates between high-power transmissions and listening intervals. Basic unmodulated CW radar is excellent for detecting moving objects but cannot directly determine their distance, because it has no pulse travel-time measurement. Frequency-modulated continuous-wave radar adds a changing frequency, or chirp, so the system can estimate range as well as velocity.

Common examples include police speed radar, sports-speed systems, motion sensors, and some missile-guidance applications. Phased-array radar describes how an antenna beam is steered, not whether the signal is pulsed or continuous. Bistatic radar describes separated transmitter and receiver locations, while synthetic-aperture radar is an imaging technique. Those categories can overlap with CW operation, but they do not define the steady-signal property in the question.