PA - RF Cafe Forums

RF Cafe Forums closed its virtual doors in late 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 2012, Facebook and Twitter were overwhelmingly dominating online personal interaction, and RF Cafe Forums activity dropped off precipitously. 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. Here is the full original RF Cafe Forums on Archive.org

-- Amateur Radio

-- Anecdotes, Gripes, & Humor

-- Antennas

-- CAE, CAD, & Software

-- Circuits & Components

-- Employment & Interviews

-- Miscellany

-- Swap Shop

-- Systems

-- Test & Measurement

-- Webmaster

sofialebbar

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 .

the probleme is how we can find the transistor model that we need to use .

and how we can find the system layout using ADS

please answer at

maha201177@yahoo.com

Top

Jeanalmira

Post subject: Posted: Sun Jun 19, 2005 9:07 pm

General

Joined: Tue Mar 15, 2005 11:43 pm

Posts: 65

Location: Singapore

Hi:

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,

Regards,

Jean

Top

sofialebbar

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 .

thanks alot for all

Top

sos

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...

You can find more info by talking to their application engineers....good luck to you

Posted  11/12/2012