| 摘要 |
PURPOSE:To obtain a compact and lightweight local oscillator having high stability by using an electrical means to vary the oscillation frequency of a VCO constituting a phase synchronizing oscillator up to the output frequencies of plural crystal oscillators and therefore starting and stopping these crystal oscillators by means of an external command. CONSTITUTION:A local oscillator consists of the 1st and 2nd local oscillation circuits 11 and 12, a synthesizing circuit 13 and a phase synchronizing oscillator 14. The oscillator 14 is provided with a VCO15, a phase wave detector 16 and a loop amplifier circuit 17. The oscillation output frequencies fX1 and fX2 are obtained from crystal oscillators 11 and 12 respectively with oscillation frequencies f1 and f2 obtained from the VCO14. Then f1=mfX1 and f2=nfX2 are satisfied (m, n: positive integers). An ON command signal is applied to an ON command terminal 19 or 21 of the oscillators 11 or 12; while an OFF command signal is applied to an OFF command terminal 22 or 20 respectively. Thus the frequencies having phase synchronization with m-degree and n-degree higher harmonic waves are delivered from an output terminal 18 of the oscillator 14. |
