TRAPATT oscillators with high frequency stability and high power

The possibility of realizing TRAPATT oscillators with high frequency stability and high power is demonstrated experimentally and theoretically. The oscillator on which the study is based is characterized as a trigger circuit with high characteristic impedance Zt in series with a diode. The triggering mechanism in steady-state oscillation is clarified by observing the voltage waveforms and the current waveforms at various points of the oscillator circuit. It is shown that the variation of oscillation frequency due to the change of load impedance is caused by the variation of triggering action due to the voltage change of load circuit. It is also shown that improved frequency stability and increased oscillation power can be realized using high Zt. Test oscillators fabricated on the basis of the above results show that the frequency stability can be improved by about two orders of magnitude and that the output power can also be increased.