Electronic – Gunn diode operation frequency

diodesmicrowaveoscillator

Gunn diodes are usually specified to work within a range of frequencies, e.g ~10GHz. I can easily understand why there is an upper bound for the frequency of operation of a Gunn diode, but I can't figure out why there is a lower bound: after all, what is used is the negative resistance of the diode: what prevent us to use this negative resistance at frequencies as low as 100hz, beside the fact that it would be very stupid to use a Gunn diode at such frequencies?

Best Answer

Limitations of self resonant choke frequency>10Ghz and high enough L to isolate the DC bias from loading the negative resistance limits the LF cutoff.