| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To suppress the effect of road surface multipath fading and to significantly reduce the measurement interferences due to multipath fading. <P>SOLUTION: A switching circuit 23 conducts alternate switchover to either a transmission-side antenna 24 for vertically polarized waves or a transmission-side antenna 25 for horizontally polarized waves, in accordance with the instructions from a comparator 36 and sweeps with a vertically or horizontally polarized high-frequency signal. Antennas 30-1 through 30-n for obliquely or circularly polarized waves receive the vertically polarized waves and horizontally polarized waves reflected from an object. The comparator 36 compares received signals stored in a memory 35, with received signals of reflected waves received after switchover of the transmission antennas, and issues instructions to A/D 34 to adopt the received signal of the polarized wave corresponding to the reflected wave of which the reception level is higher, while issuing instructions on switchover of the transmission antennas to the switch circuit 23. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
