SPICE models for big fat RF transistors

[Joerg]

EE123 wrote:

Joerg,

You might to reconsider the decision to build a switch to measure
VSWR.

You might want to look at gradually decreasing power as the VSWR goes
up.
If you switch everything at once, you will have a very large arc as
the power has to
go somewhere ( usually a place that you don't want it to)
There are companies out there that make VSWR protection circuits but
they
have be integrated into the PA in some fashion.

I can't go gradual because the switch action is what will actually
happen in this application. Near-shorts, full and sudden interruption,
and so on. It needs to survive that. The usual SWR protection circuits
rely on bridges, multipliers and whatnot, typically after rectifying the
phase-coupler outputs. By the time the rectified signals show up it'll
already be ... phut ... *KABLAM*

--
Regards, Joerg

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