As shown in the diagram, the faint resonant signal is obtained from the RF cavity (depicted here as a lumped LC element) with the help of a Superconducting Quantum Interference Device and a tunnel diode
front-end detector and mixed with a 300 KHz modulation signal from an ultra-low distortion Signal Generator in our laboratory (Stanford Research DS360).
Applications for these nitride (AlGaN/GaN) double barrier heterostructure based tunnel diodes
included local oscillators for UHF television tuners, trigger circuits in oscilloscopes, high speed counter circuits, and very fast rise time pulse generator circuits [1, 3].
With the evolution of technology, the variety of devices used for generating ultra-short steps or pulses has expanded to include gallium arsenide (GaAs) photoconductive switches, (3-4) mercury switches, avalanche transistors, step recovery diodes (SRD), tunnel diodes
and avalanche diodes, etc.
'Interesting as the hydrogen atom and the microwave experiments are, a novel tunnel diode
and devices like it are more likely to show up in practical applications,' notes Eric J.
Scientists first convincingly demonstrated the electronic tunnelling phenomenon in semiconductors in the late 1950s, and since that time it has become the basis of several electronic components--among them tunnel diodes
, which are good for some amplification and high-speed switching applications.