| 摘要 |
PURPOSE:To measure the range up to an object with high precision, by passing signals of slightly different frequencies through exactly the same route and measuring delay time on real-time basis. CONSTITUTION:After a transmission frequency is modulated by a tone for transmission distance measurement and amplified, the resulting signal is sent out of an antenna 1. The sent radio wave arrives at the object and is relayed and received by the antenna 1 again. The received signal is demodulated by a receiver 10 after low-noise amplification and frequency conversion and a tone extractor 11 extracts the tone for range measurement. The output signal of a transmitting amplifier 2 is distributed and extracted by a coupler 15 and converted to such a frequency that the receiver 10 can not acquires it; and the resulting signal is supplied to a coupler 16 for low-noise amplification and frequency conversion together with the received signal, a receiver 8 imposed demodulation, and a tone extractor extracts the tone for range measurement. The tones extracted by extractors 9 and 11 are supplied to phase meters 12 and 13 to measure their phase differences from the tone for the transmission distance measurement, and those measured values are supplied to a subtracter 14 to obtain the difference; and the delay time variation of a transmitting and receiving system circuit is canceled to realize high-precision measurement. |
