A doubly-tuned coupled resonant gate transistor

Singly resonant silicon tuning transistors have been reported. Multiresonant mechanical structures, properly constructed, can result in filters with flat passband and steep rejection slopes. We report a batch-fabricated twin cantilever RGT containing a coupling web near the clamped end. Under one beam is the electrostatic input electrode; under the other beam is the channel of the MOS detector. The beams can vibrate collectively in two modes. If the web width is adjusted properly, the two mode frequencies will be about fo/Q apart resulting in approximately flat doubly-tuned bandpass properties.