FET oscillator having controllable reactance element-controlled two port feedback network

Claim 1

An oscillator for delivering maximum radio frequency output power to a load and comprising: a field-effect transistor having a surce terminal, a gate terminal and a drain terminal; and a two-port network having an input port connected across the drain and the source terminals of the field-effect transistor, and an output port connected across the gate and the source terminals of the field-effect transistor, the network consisting of three branches connected in T-configuration, each branch radiating outwardly from a node to the drain, source and gate terminals of the field-effect transistor respectively, each of the first and second branches including a controllable reactance element comprising a first varactor and each of the first and second branches includes a second varactor connected in series with the first varactor by an inductance coil, and the third branch including the load.