Abstract: A field effect transistor structure includes a single crystal substrate having: a source, gate and drain electrodes disposed on an upper surface of the substrate, the gate electrode having a region thereof disposed between a region of the drain electrode and a region of the source electrode; a ground conductor disposed on a lower surface of the substrate; a plurality of electrically conductive vias passing through the substrate, each one of the vias having one end electrically connected to a different region of the ground conductor and having another end electrically connected to the gate electrode. The plurality of electrically conductive vias provide parallel and symmetric connections between the gate electrode and the ground conductor.

Abstract: A radio frequency oscillator having: a resonant circuit; a gain element coupled in feedback relationship with the resonant circuit; and a variable reactance device, such as a varactor diode, adapted for coupling to a control signal for varying the reactance of the device. The variable reactance device is coupled to the resonant circuit with a coupling factor less than one. The resonant circuit comprises a planar microstrip transmission line structure. The varactor diode is coupled to the microstrip transmission line through a strip conductor disposed adjacent to, and dielectrically spaced from, a strip conductor of the resonant circuit. In one embodiment, the strip conductors are disposed in a side-by-side, dielectrically spaced relationship. In another embodiment, the strip conductors are disposed in a face-to-face, dielectrically spaced relationship.