Post subject: 1700-1900MHz 20w RF amp Posted: Thu Jan 15, 2009
Joined: Tue Aug 26, 2008 5:18 am
can any one advise me which transistors
are available for designing 20w, 24-28V balanced RF amp to cover 1.7-1.9GHz
band. I am using Microwave Office so it will be nice to have a device
whose model is available in MWO like freescale.
Post subject: Re: 1700-1900MHz 20w RF ampPosted:
Fri Jan 30, 2009 5:10 pm
Joined: Mon Jun
27, 2005 2:02 pm
Take a look at Infineon line of RF Power Transistors.
http://www.infineon.com/cms/en/product/ ... Power.html
recent experience with them, I know they also have models for MWO.
Post subject: Re: 1700-1900MHz 20w
RF ampPosted: Thu Feb 19, 2009 6:47 am
Tue Aug 26, 2008 5:18 am
Thanks for your reply. I've designed 20W PA (balanced Class A) operating
from 1700MHz to 1900MHz using MRF19030 Transistors from Freescale.
Re: 1700-1900MHz 20w RF ampPosted: Mon Mar 30, 2009 4:52 pm
Just to add some thoughts to your selection:
MRF19030 transistor form Freescale might be obsolete or in the way,
perhaps you want to take a look to the Freescale 5th or 6th generation
LDMOS amplifiers (MRF5... MRF6...) they are more efficient and rough
(difficult to burn by a fair output load).
Also, you asked for a
Class A operation, these Freescale transistors were designed to work
as Class AB... I think if you try to make it work into a Class A operation
you might end up having a lower P1dB.
-A 30W transistor for 20W
sound like a good choice from the fact that you will have to use a very
broad band match (many match stages---> more insertion loss) to meet
the specs from 1.7 to 1.9GHz.
-Remember to add a circuit to compensate
the bias point drift over temperature, specially if you plan to use
it in a high bias point where you will have a lot of heat generation
( I assumed this from the fact that you asked for a class A amp) .