3. Notions on continuous radars

3.1 Basic principle

In cases where we are only interested in target speed :

• speed control ;

• doppler navigation ;

• detection of the presence of fixed echoes in a medium.

The simplest solution is to emit a continuous wave of a specific frequency, and measure the difference between the frequency of the received wave and the frequency of the emitted wave.

The schematic diagram, shown in figure 34 , uses a coherent transmit-receive chain and two separate antennas.

These radars are simple in design,...