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January 20, 2011


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George Storm

"My boss at the time may have suspected that I dabbled in the occult arts. I was never sure with that guy."
I had several bosses who appeared to believe that all microwave engineering was black art. Being innocent I never thought to utilise this in salary negotiations.
BTW, I had a similar problem with cavity resonance - that one was solved by sticking a bit of carbon-loaded foam in the middle of the lid (so no "circuit change" or board modification - does that count?)

John D.

George, the foam idea was great! I'll never know if it would have counted though, that boss' whereabouts today are quite unknown.


same problem back in the 80's at x-band in a MIC module. used George's solution but silicone sheet loaded with iron powder (magram) mounted to the inside of the lid temporarily until circuit was redesigned.

Mattias F

Oscillations due to cavity resonance are a true classic! As a curiosity it is in some cases possible to reduce the problem with a simple pencil by sketching on the lid. The graphite dampens the modes.

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