Hey Phil Here is a really good one.

A typical ft of 42 GHz makes it fast, but you've been able to buy parts just as fast for quite a while now. What makes it worth commenting on?

Looks good and cheap and in stock. I might have to get a few.

Yup. I use its little brother (BFP640) a fair amount as the cascode device for 10-mA class pHEMTs. They're pretty squirrelly though--high gain and sup er-high fT makes them want very badly to oscillate around 14 GHz. Usually I just put a Murata BLM18BB-series 5- or 10-ohm bead in the base, which make s them behave.

Trashes the BW of course, but their other virtues survive: high gain and re ally amazing linearity.

The pHEMT/SiGe cascode is very close to the ideal RF device--the only drawb ack is the high 1/f corner.

Cheers

Phil Hobbs