Digitally-controlled calibrator for measurement and testing of CW doppler radars

CW Doppler radars are often used for short-range detection of moving targets and measurement of their velocities. Beside the basic analog structure, the CW radar family also includes more complex FMCW or digitally modulated types of radars. The dynamic range of these sensors can be substantially enhanced by means of the HW elimination of static reflections and cross-talks, which complicates calibration and testing procedures. Consequently, the radars can be tested only by using moving targets, yet this can be costly and time-consuming. That is why a stationary calibrator able to simulate moving targets with a well defined RCS and velocity can be very useful. The presented paper describes the design, realization and testing of such device capable of simulating moving targets within the 8-12 GHz frequency band. As the calibrator is digitally controlled, well defined and precise parameters are reached.