| 摘要 |
Provided is a system (100) including a Doppler radar unit (102) transmitting a first electronic wave (106) having a first frequency. A test system (104) converts the first electronic wave into a first electric signal having the first frequency. The test system (104) generates a second electric signal having a second frequency, and mixes the first electric signal and the second electric signal for generating a third electric signal having a third frequency which is a sum or difference frequency. The third frequency presents a Doppler-shifted frequency caused by reflections of the first frequency (106) by a target dropped from the Doppler radar unit (102). The test system (104) converts the third electric signal into a second electric wave (108) having the third frequency, and retransmitting the second electronic wave to the Doppler radar unit (102) for calculation of speed of a target with a function of the first frequency and the third frequency, thereby calibrating/detecting the Doppler radar unit (102). |
