A K-BAND MONOLITHIC OSCILLATOR INTEGRATED WITH A BUFFER AMPLIFIER USING A DEVICE-CIRCUIT INTERACTION DESIGN CONCEPT

We report on a high power, high efficiency, and small-size monolithic coplanar waveguide oscillator incorporating a single-stage buffer ampl ifier on the same chip, For the oscillator design, by changing RF curr ent level through the device, the optimum load line was chosen in orde r to have an oscillation frequency insensitive to the effect of the su bsequently connected amplifier, based on a device-circuit interaction concept, The amplifier, on the other hand, which was driven directly b y the oscillator, was designed to achieve an overall high power and hi gh efficiency operation, At 21 GHz, the output power of the developed chip recorded 17 dBm with an overall dc-RF efficiency of 22%. By chang ing the length of a source feedback line, the oscillation frequency wa s varied from 21 GHz to 26 GHz, For all cases, the output power remain ed higher than 16 dBm.