Self-pumped Gunn-effect parametric amplifier

The letter reports the operation of a degenerate parametric amplifier which utilises the self-pumping action of the oscillating domain capacitance in the Gunn effect. Gains greater than 20dB at 5.98GHz have been obtained with the Gunn sample oscillating at 11.96GHz. Amplification is also reported in the normal negative-resistance mode, and an experiment is described which is designed to distinguish between the two modes of amplification.