| 摘要 |
1518256 AFC systems SIEMENS AG 19 Jan 1977 [27 Feb 1976] 02042/77 Heading H3A In a frequency stabilizing arrangement for an oscillator 1 suitable for operation at micro-wave frequencies and in an FM modulation arrangement, frequency discriminating action in respect of deviations from a nominal centre frequency is provided by the combination in a 3dB coupler 5, detector 6 and amplifier 7 of oscillator output signals supplied via a path including a resonator 3 and a direct path including a line 4 compensating any phase differences introduced at an input coupler 2 or due to difference in line lengths of the two paths and the error voltage produced controls the oscillator frequency. The resonator 3 may be a dielectric, filled in or cavity resonator and may be connected in shunt (Figs. 2,4 not shown) instead of in series to the signal path. In Figs. 3,4 (not shown), the path via the resonator includes a further coupler. |
