| 摘要 |
PCT No. PCT/SE89/00566 Sec. 371 Date Jun. 3, 1991 Sec. 102(e) Date Jun. 3, 1991 PCT Filed Oct. 16, 1989 PCT Pub. No. WO90/04761 PCT Pub. Date May 3, 1990.Arrangement for transmission and reception of electromagnetic radiation. A transmitting and receiving part (1) transmits and receives the electromagnetic radiation, and a reflecting part (2) reflects the transmitted electromagnetic radiation back to the transmitting and receiving part while passing through a medium which transmits radiation. The transmitting and receiving part has an electromagnetic radiation source (5) and a concave main reflector (3) which is common to transmission and reception. The transmitting and receiving part has a second reflector (6), which is positioned between the radiation source (5) and the main reflector (3), so that this second reflector shades a part of the main reflector reflecting area (4) for the radiation transmitted by the radiation source towards the main reflector. This forms a shadow area (17) on the main reflector reflecting area for transmitted radiation. This second reflector receives a part of the reflected radiation from the main reflector and reflects this back towards a detector for reception of the radiation. The shadow area for transmitted radiation also has a reflecting receiving area for the radiation which is incident upon the main reflector and reflected back towards the detector by the second reflector. The remaining part of the main reflector reflecting area, which is not shadow area for transmitted radiation, forms a transmitting area for the radiation which is transmitted by the radiation source and reflected in the main reflector. |
