| 摘要 |
There is a manufacturing limit on how small ceramic coaxial resonators can be produced, which leads to a limit on the frequency of resonance for these resonators. One technique to double the effective frequency of a ceramic coaxial resonator is to couple each end of a resonator to a Colpitts oscillator, the oscillators being balanced and out-of-phase by 180 DEG . During operation, the resonator is effectively divided in half with a virtual ground forming in the center. This allows a single resonator to operate as two resonators of half the original size. Hence, the oscillation frequency for each of these balanced oscillators is doubled when compared to the frequency of similar oscillators that have separate ceramic coaxial resonators of similar size. If this technique is further implemented within a push-pull design tuned to the third harmonic, the output oscillation frequency becomes six times that of an oscillator using a separate ceramic coaxial resonator of similar size. This technique expands the range of use for a ceramic coaxial resonator so that, if used along side a subharmonically pumped mixer that allows for doubling of the local oscillator frequency, the maximum oscillation frequency is increased ideally to 60 GHz. This frequency range allows ceramic coaxial resonators to be used for high frequency applications such as LMDS. |
