Thermally induced FM noise in Gunn oscillators and jitter in Gunn-effect digital devices

By considering the starting-time fluctuation of domain formation and the fluctuation of domain-formation time caused by thermal noise, the front-edge fluctuation of the output current pulse of a Gunn device is obtained. Taking the Fourier transform of the output current-pulse train with these front-edge fluctuations, we obtain the equivalent noise-current source due to the thermal noise of Gunn oscillators. Solving Kurokawa´s oscillator equation including this equivalent noise-current source, an expression for thermally induced FM noise in Gunn oscillators is derived. The result is in good agreement with experimental data. These results are applied to estimate thermally induced jitter in Gunn-effect digital devices.