Frequency modulated superconducting resonators

High Q superconducting resonators whose resonant frequencies can be mechanically modulated over a wide range at a rapid rate have been developed. In the few hundred megahertz range, frequency modulation (FM) of these resonators by nearly a factor of three has been achieved at modulation rates up to two kilohertz. Mechanical techniques for producing large FM are being developed in order to achieve efficient electromechanical energy conversion in these devices. This paper reports analyses and experiments on the time evolution of stored electromagnetic energy under adiabatic FM conditions. The behavior of coupled FM superconducting resonators as a microwave switch is also illustrated by computer simulation. Application of the coupled FM resonators to the generation of very high power microwave pulses is discussed.