| 摘要 |
PURPOSE:To improve low noise and separation performance and stability by using a ring structure resonator as a dielectric element so as to utilize the steepness of the phase characteristic of the said ring resonator. CONSTITUTION:The resonator of ring or loop structure consists of a microstrip line 501, a capacitor 502 and an input terminal 503. A parallel resonance point frp exists in the vicinity of a series resonance point frs in the capacitance loading type resonator, the resonator satisfies the oscillating condition between the points frs and frp and the phase change between the points frs and frp is very steep in comparison with that of a conventional resonator, then the resonator is used as a resonator with excellent oscillation spectrum. Since the resonance circuit section is arranged to be opposed to an active circuit section 109 via the resonance circuit, an output buffer amplifier 110 and an oscillation active circuit section 109 are parted spatially, the stray coupling is reduced, the spurious oscillation of the oscillation circuit is reduced and the effect of load fluctuation is decreased. |
