Post subject: TRANSISTOR FOR EFFICIENT 900 MHz, 100mW
Unread postPosted: Thu Sep 02, 2004 6:59 am
suggestions on a nice transistor for a PA at 900MHz with good efficiency?
Pout: 50 to 100 mW
Supply rail: 3 Volts
Class: Probably C or harmonic
terminated etc (need best efficiency)
Efficiency: Target of better
Transistor type: Fet or Bipolar
Size: Small parts
Cost: Not critical
Post subject: Any suggestions on a nice transistor for a PA
at 900MHz with
Unread postPosted: Thu Sep 09, 2004 2:08 pm
I've had some great luck with an Infineon BFP450
levels, efficiencies and frequencies. Hint
use a constant current
100 mW amp
Unread postPosted: Sat Sep 11, 2004 9:03 am
Don't know if this is better, the efficiency may be a bit off,
but talk about simple...
Guest - IFX
Unread postPosted: Sat Sep 11, 2004 11:42 pm
Use only Infineon BFP450 for your application. It is very stable
and easy to tune to 900MHz.
It is a SiGe Device with Ft of
If you need more gain add BFP420 / BFP
520 / BFP 620 as a driver to your +20dBm PA.
Guest - IFX
Unread postPosted: Mon Sep 13, 2004 9:12 am
Thanks to you all,
Strange (or maybe not) but I ended
up prototyping a BFP450 amp last week. Performance is reasonable
without trying very hard (circa 45 to 50% collector eff') but quite
a bit harder to get any more efficiency than that. I tried a harmonic
termination of 2F and then 3F but this did not gain me much for
quite a bit more complexity!
Thanks again anyway