A 13-GHz YIG-film tuned oscillator for VSAT applications

A description is given of 13-GHz tunable oscillator using YIG film grown by liquid-phase epitaxy. A very low phase noise of -90 dBc/Hz at 10 kHz from the carrier was achieved over the entire tuning range of 500 MHz. The design criteria for the YIG disk resonator and the biasing condition of GaAs FET needed to achieve the low phase noise and avoid high-power instability are discussed. The tuning characteristic and the oscillator performance over temperature is presented. The output power of the oscillator was over 6.6 dBm without using the output buffer amplifier. The variation of the output power over the tuning range from 13 GHz to 13.5 GHz was less than 0.3 dB, and the hysteresis of the oscillation frequency was less than 1 MHz. The temperature drift was 10 MHz from -30 degrees C to +60 degrees C. The excellent linear tuning characteristic of this oscillator makes it ideal for use as a frequency-agile synthesized local oscillator in a very small aperture terminal (VSAT).<>