摘要 |
A main CPW structure is formed by depositing two parallel films of a conductor on a film of a single crystal ferroelectric material. Cavities are formed by placing irises in a main CPW structure. These cavities are tuned to a dominant resonant frequency. By the application of a bias voltage to the main CPW structure with cavities, the permittivity of the film of the ferroelectric material, underneath the CPW structure, is changed. Thus the dominant resonant frequency of the filter is changed. By changing the level of the bias voltages, different dominant resonant frequencies of the filter are obtained. Thus a tunable band pass filter is obtained. With branch cavities on a CPW structure deposited on a ferroelectric film, a tunable band reject filter is obtained.
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