| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To obtain a phase change between the transmission wave and the reception wave with a simple configuration. <P>SOLUTION: A phase of a carrier signal is modulated by a lamp signal, and waveform is shaped in a waveform shaping circuit 8 so that its falling or rising is steeper, and thus generated higher-order harmonics wave is transmitted from a transmitting antenna 10. A reflection wave reflected by a target is received by a receiving antenna 11. Not only the microwave transmitted by the transmitting antenna, but also any of the reflection wave received by the receiving antenna is made to be the modulated wave by the lamp signal. Therefore, a base band signal including phase modulation can be obtained by a simple circuit configuration by a low-pass filter, and the phase change by the phase modulation of both of them can be obtained with the usage of a differential amplifier 23. A cut-off frequency of the low-pass filter is set to be the frequency corresponding to a ratio of the frequency of the carrier signal and the frequency of the lamp signal. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
