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:
AMPLIFIER_200_400MHz - 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: AMPLIFIER_200_400MHz Posted: Thu Nov 03, 2005
Joined: Thu Nov 03, 2005 5:34 pm
I want to make about following parameters
I need relating information:
- the influence of temperature
on parameters the VDMOS, LDMOS.
- the selection of transistors (what
- on what was one should be careful,
I found the
solution firms polyfet, motorola, philips, macom.
Are yet some firm
thanks for information
subject: Posted: Sat Nov 05, 2005 11:23 am
Joined: Mon Jun 27, 2005 2:02 pm
The vendors you mentioned are the right
ones. You should carefully check for the right device. Most of the vendors
provide an application circuit for each device. The most important part
of a PA circuit are the matching networks in the input and output. These
networks also are designed for the required BW of operation. Your BW
is octave, which is very wideband. So you should carefully examine this
You should also pay attention to the bias feesing circuit.
There should be a good isolation between the the RF output and the DC
supply, and the bias level should be adjusted to provide the required
linearity and output power level.