Coaxial resonator and oscillation circuits featuring coaxial resonators

Abstract

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°. 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. This technique expands the range of use for a ceramic coaxial resonator so that, if implemented within a push-push architecture and if used along side a subharmonically pumped mixer that allows for doubling of the local oscillator frequency, the maximum oscillation frequency is increased to 40 GHz. This frequency range allows ceramic coaxial resonators to be used for high frequency applications such as LMDS.

Dependencies are inferred from the claim text.