Copyright: 1996 - 2024
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling
2 MB. Its primary purpose was to provide me with ready access to commonly needed
formulas and reference material while performing my work as an RF system and circuit
design engineer. The World Wide Web (Internet) was largely an unknown entity at
the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps
while tying up your telephone line, and a nice lady's voice announced "You've Got
Mail" when a new message arrived...
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My Hobby Website:
PA - RF Cafe Forums
RF Cafe Forums closed its virtual doors in 2012 mainly due to other social media
platforms dominating public commenting venues. RF Cafe Forums began sometime around
August of 2003 and was quite well-attended for many years. By 2010, Facebook and
Twitter were overwhelmingly dominating online personal interaction, and RF Cafe
Forums activity dropped off precipitously. If the folks at
phpBB would release a version with integrated
sign-in from the major social media platforms, I would resurrect the RF Cafe Forums,
but until then it is probably not worth the effort. Regardless, there are still
lots of great posts in the archive that ware worth looking at.
Below are the old forum threads, including responses to the original posts.
|-- Amateur Radio
Gripes & Humor
-- CAE, CAD, &
Test & Measurement
Post subject: PA Posted: Fri Jun 17, 2005 7:50 am
am new in microwave power amplifiers.
I can build the system
using couple of tranistors , capacity and inductors .
is how we can find the transistor model that we need to use .
how we can find the system layout using ADS
please answer at
Posted: Sun Jun 19, 2005 9:07 pm
Tue Mar 15, 2005 11:43 pm
For choosing transistors for RF PA, you need to consider the
specifications of the PA, such as how much gain are you needed, how
much power and linearity to be achieved. and whether it's single-stage
or multi-stages PA?
For example, at multi-stages PA, usually
we use high-impedance transistor at first stage and low impedance transistor
at last stage. The high impedance gives us lower input reflection with
simpler input and interstage matching networks .
While the high
impedance at the last stage (output side) will give us some room for
power matching at the end.
and also , you may consider the gain
you need, and check the GMax of the transistors, and see whether it
is possible to achive certain gain.
If you could provide me more
details, I might be able to help you.
Hope it helps,
Post subject: PAPosted:
Wed Aug 10, 2005 3:54 pm
thanks alot for answering my request .and
sory for not responding earlier n that time
in fact my problem is
when designing the PA , i needed to choose a model for my FET transistors
(am using ADS software), and i don't have one.so do u need any place
were i can telecharge the library that i will need .
Post subject: Posted: Thu Aug
11, 2005 7:31 pm
You can visit some transistor supplier for more
infor: advanced power technologies RF, macom or philip...
can find more info by talking to their application engineers....good
luck to you