A frequency stabilizing method in an oscillator, using correlation between phase and amplitude noises in transistor

In older to give the clearer picture of the excess noise mechanism and to develop the noise reduction method, we measured the phase and amplitude noises, and their correlation coefficient in collector current. The noise generating mechanism is discussed with the diffusion coefficient fluctuation in the base. A possible noise reduction method is demonstrated, using the correlation between the phase and amplitude noises. We prepared a most fundamental phase-shift type transistor oscillator to measure the frequency and current fluctuations simultaneously, and the correlation coefficient between them. We find both fluctuations correlate each other in low frequency. The frequency stabilization technique is discussed and a new method to reduce the frequency fluctuation is proposed in an oscillator, using the correlation.