| 摘要 |
1182-9 ADJUSTABLE RESONATOR ARRANGEMENT An adjustable resonator arrangement comprises a main resonator (T1) and a secondary resonator (T2) reactively coupled thereto. The secondary resonator includes a switching element (S), e.g. a varactor, having at least two states. When the switching element is in a first state the secondary resonator behaves as a half-wave resonator having a resonant frequency fo substantially different to the resonant frequency f of the main resonator. Consequently the secondary resonator has no appreciable affect on the resonant frequency of the main resonator. However, when the switching element is in a second state, the secondary resonator behaves as a quarter-wave resonator having a resonant frequency 2*fo which is closer to the inherent frequency f of the main resonator and sufficiently close to cause a shift .DELTA.f in the effective frequency of the main resonator. Suitably the main resonator is realized as a dielectric resonator and the secondary resonator is realized as a strip line resonator in the form of a conductive strip provided on a side face of the dielectric block from which the main resonator is formed.
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