A 2-5 GHz tunable magnetostatic wave oscillator

A prototype 2-5 GHz tunable magnetostatic wave (MSW) delay line oscillator has been developed. The continuous frequency sweep range is between 1.8 GHz and 5.6 GHz. SSB (single sideband) phase noise characteristics at 10 kHz offset frequency are better than -111 dBc/Hz. The oscillation power level has been carefully controlled because a saturation of a MSW delay line degrades the inherent SSB phase noise of the line by 40 dB at 10 kHz offset frequency. The degradation of the inherent SSB phase noise directly affects the output signal. The frequency drift rate changes from 6.8 MHz/K to 2.8 MHz/K for 2-5 GHz almost linearly. The drift was stabilized within +or-20 MHz for the temperature range from 270 K to 340 K by sensing YIG film temperature and adjusting tuning coil current.<>