Technique allows simple design of microwave DROs

A new type of highly stabilized GaAs FET oscillator using a dielectric resonator and a stabilized resistor in the feedback circuit has been developed. The oscillator fabricated with a microwave integrated circuit has a high external quality factor. Dielectric-resonator oscillators (DROs) offer such advantages as good frequency stability, the possibility of tuning with varactors, and simple, low-cost construction. A DOR design method is available that combines accuracy and simplicity as it requires only small-signal parameters (which are typically available from manufacturers). The microwave characteristics of the GaAs FET oscillator have revealed: 1) High efficiency of 20 percent output power at 10 GHz, 2) a wide tuning range more than 1000 MHz, 3) a wide oscillation frequency from 9 to 14 GHz with same MIC pattern by using five dielectric resonators of different sizes, 4) a high-frequency stability as low as 150 kHz in the temperature range from -20 to +60 °C.