| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect a plurality of targets at near and far distances with radar in a radar transmitter/receiver used for preventing the collision of an automobile. SOLUTION: Normally, an FM pulse wave that is oscillated by an SOM (frequency mixer) 2 is transmitted by an antenna 1, a reflection wave from an object is received by the antenna 1 and is taken out as an intermediate frequency signal by the SOM 2, and signal processing is made by a signal processing part 6 for FM pulses, thus detecting the object at a far distance. When a DSP 7 judges that there is a close target, it outputs a switching signal and switches the oscillation of the SOM 2 to an FM-CM wave, transmits the FM-CW wave from the antenna 1, receives a reflection signal from the target by the antenna 1, and takes out a beat signal by the SOM 2. Then, the signal is processed by the signal-processing part 9 for FM-CW to detect the object at a close distance.</p> |
