| 摘要 |
An electromagnetic-wave marker includes a bar-like receiving antenna for receiving an electromagnetic wave, a frequency converting circuit coupled to the receiving antenna and for multiplying a frequency of the electromagnetic wave, a disc-like transmitting antenna for transmitting an electromagnetic wave of which frequency is multiplied by the frequency converting circuit, a nonmagnetic container for accommodating and placing the receiving antenna and the transmitting antenna such that the received electromagnetic wave and the transmitting electromagnetic wave intersect with each other at right angles, and an electromagnetic-wave reflector placed at a lower portion of the nonmagnetic container and for reflecting the electromagnetic wave along the transmitted direction. The marker is improved its anti-corrosion property, and at the same time, reduces its thickness, so that the marker can be laid down in various structures of roads such as an iron bridge.
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