A HIGHLY STABILIZED GAAS-FET REFLECTION-TYPE OSCILLATOR WITH A DIELECTRIC RESONATOR IN X-BAND

A reflection-type dielectric resonator oscillator (RTDRO) that provides a highly stable, low phase noise signal is described. Numerical simulation providing an optimum aspect ratio (diameter/height) range of a cylindrical dielectric resonator (DR) is investigated for preventing spurious mode resonances. The DR of Ba(Zn1/3/Nb2/3)O3 (BZN, tau-f = +7 ppm/degrees-C, epsilon(r) = 33) applied in the reflection-type oscillator not only acted as the frequency determining element, but also reduced the oscillator's temperature drift. The effects of a DR coupled to a microstrip line with varying coupling position as well as the RTDRO's output characteristics are investigated in this paper. The frequency temperature coefficient of the RTDRO from -10-degrees-C to +90-degrees-C is +/- 0.83 ppm/degrees-C at 9.46 GHz and the phase noise is below -107 dBc/Hz at 100 kHz off carrier frequency. It exhibits an available output power of 14.2 dBm with 13.8 percent power efficiency.