High-Efficiency Avalanche Resonance Pumped Amplification

Silicon diodes pulse operated in avalanche resonance pumped modes have produced stable microwave amplification with up to 25 percent dc to RF conversion efficiency. The p⁺-n-n⁺ diodes were mounted in a coaxial line resonator. Under conditions of self-generated pump signals at or close to the avalanche resonance frequency between 8.8 and 10.4 GHz, a low-power gain of 19, 20, end 16 dB was measured at 1.3, 3.2, and 4.4 GHz, corresponding to the seventh, second, and first subharmonic. At 1.3 GHz, a high-power gain of 12 dB resulted in a dc to RF conversion efficiency of 25 percent. The normalized (gain)¹2/ X bandwidth product was 12 percent. Amplifier saturation related to decreasing pump amplitudes is reported.