Tunable L-Band High-Power Avalanche-Diode Oscillator Circuit

A simple coaxial circuit has been designed for use with the high-power anomalous-mode avalanche diodes. Pulsed powers of over 100 watts with efficiencies of 25 to 30 percent are typically obtainable from single chips and as much as 180 watts at 40 percent efficiency has been achieved. The frequency of oscillation is continuously tunable from 1.0 to 1.5 GHz with variations in output power of approximately 1 dB. It has been demonstrated that the circuit must be capable of supporting higher order harmonics of the fundamental anomalous-mode oscillations for proper operation. The simplicity of tuning and the consistency with which these diodes can be fabricated indicates that in the near future these devices may play a role in practical systems.