The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Design >> RF Design >> Biasing for PA IC's
https://designers-guide.org/forum/YaBB.pl?num=1140558082

Message started by mxkdirs on Feb 21^st, 2006, 1:41pm

Title: Biasing for PA IC's
Post by mxkdirs on Feb 21^st, 2006, 1:41pm

Hello all,

This's my first post here. I never knew about this site. This definitely won't be my first post---I ask too many questions. Can anyone point me to references for biasing circuits for PA's, espcially BJT/HBT based PA's. Specfically, I need a good yet simple constant current biasing circuit. As anyone who works with PA must know there's hardly any good book on PA IC design and hence it's hard to find references. Although I would like to read up on different biasing schemes my main concern here is that for HBT constant current biasing I need a circuit that has relatively low impedance looking from the base of HBT (not more than ~350 Ohms or so). The reason is that I operate above BVceo (or Johnson Limit) and to do so I need to allow, at high electric fields, the holes flowing from collector to exit through base and shunt to ground instead of going into emitter and increasing Vbe and thus increasing Ic and causing avalanche breakdown. Thanks a bunch

Mike