Synchronization and Noise Performance of Two-Frequency Oscillators

A nonlinear theory of multiple-frequency oscillators of the negative resistance type is developed and applied to two-frequency Gunn- and Impattdiode oscillators. The following results which were confirmed by measurements are obtained: By a high-Q loading of the second circuit a considerable improvement in the FM-noise spectrum at the fundamental frequency is achieved. The locking bandwidth is nearly twice that of a (sub-) harmonically synchronized single-frequency oscillator. The same is true for the frequency range of FM-noise reduction.