| 摘要 |
<p>PURPOSE:To simplify the function check of the Doppler radar system including the antenna part, by detecting existence of the Doppler signal caused by idling of the engine for vehicle and vertical movement of approximately 10Hz generated for running. CONSTITUTION:The Doppler signal generated by antenna 4 and high-frequency circuit 5 is input to wide-band amplifier 9 through capacitor C1 and is input to band pass filter 10 and low-pass filter 12. The output signal of band pass filter 10 is used as a vehicle speed signal. Next, the output of low-pass filter 12 is input to detecting circuit 13 and is converted to a DC voltage proportional to the signal accompanied with vertical movement of the vehicle, and it is detected by operational amplifier OP4 whether this value is larger than a set value or smaller than it. Characteristic check of the radar can be performed by the output signal state of detecting circuit 13. Consequently, characteristic check as the Doppler radar system including the antenna part can be performed only by adding a simple circuit.</p> |
