| 摘要 |
PURPOSE:To srabilize the frequency of an oscillating modulator oscillating at a transmission frequency and that of a local oscillator by sum and difference frequencies of a standard oscillator which oscillates at frequencies half as high as the sum and difference between the transmission frequency and local oscillation frequency. CONSTITUTION:The output of standard oscillator 8 oscillating at a frequency half as high as the sum frequency of a transmission frequency and local oscillation frequency and that of standard oscillator 9 oscillating at a frequency half as high as the difference frequency are mixed together by mixer 10 and a sum wave and difference wave are extracted by BPF11 and applied to either transmitting-receiving detector 12 or 13. In a transmitter, the output of oscillating modulator 1 is applied to detector 12 and a phase difference is obtained by a comparison to control the frequency of the modulator. In a receiver, the output of oscillator 14 is applied to detector 13 to control the frequency of the local oscillator. Therefore, neither the oscillating modulator nor receiving local oscillator requires a highly-stable oscillator, so that an oscillator of simple constitution can be realized. |
