| 摘要 |
<p>PURPOSE:To provide for an FM-CW radar device achieving restriction of FM-AM conversion noise inexpensively. CONSTITUTION:A frequency modulation means 10 for performing frequency modulation of a modulation wave to obtain a transmission wave, a branching means 12 for branching one portion of the transmission wave to a reception side, a transmission antenna 14 for transmitting the transmission wave toward a target object 16, a reception antenna 18 which receives electric wave which is reflected by the target object 16, a mixer 20 which mixes one portion of the transmission wave which is branched by the branching means 12 and the reception wave which is received by the reception antenna 18 and then outputs them, a variable attenuation means 22 which attenuates the modulation wave with a variable attenuation ratio and then outputs it, an operation means 24 which subtracts an output of the variable attenuation means 22 from an output of the mixer 20 and then outputs it as a beat signal, and a noise level detection means 26 which detects a level of an FM-AM conversion noise within the beat signal and then outputs a signal of voltage corresponding to the noise level. The attenuation ratio of the variable attenuation means 22 is controlled according to an output power of the noise level detection means 26.</p> |
