Empirical Investigation of Loudspeakers as Test-Targets for Continuous-Wave Radar

Loudspeakers provide a low-cost solution to implement vibrating radar targets. This contribution empirically investigates the reflection characteristics of loud-speakers used to test continuous-wave (CW) radars. Four different loudspeakers under test are analyzed. The radar receive signal only varies in phase when displacing the loud-speaker while it is not fed. In contrast, the receive signal varies in phase and amplitude when the loudspeaker vibrates. The resulting variation in radar cross section (RCS) and phase is determined by measurements at 61 GHz for different vibration frequencies and feed amplitudes.