| 摘要 |
<P>PROBLEM TO BE SOLVED: To adjust the azimuth of an antenna of a radio communication system in a short time by detecting received power, even when the intensity of a millimeter-wave signal received by a receiver is low. <P>SOLUTION: A transmitter 100 transmits a millimeter wave signal intensity-modulated at a frequency for power detection that is lower than the frequency of a millimeter wave as a carrier by using an automatic bias voltage adjusting mechanism of an optical modulator 103, and the receiver 200 measures the intensity of a signal component of frequency for power detection extracted from the received millimeter-wave signal and estimate the intensity of the millimeter-wave signal, based on the measured intensity. Consequently, even when the intensity of the millimeter-wave signal is small because of noise, and the like, since high S/N is obtained, as compared with a conventional case wherein a DC voltage output from a millimeter-wave detector is obtained according to the intensity of the received millimeter-wave signal, the reception sensitivity is improved. <P>COPYRIGHT: (C)2008,JPO&INPIT |
