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...
All trademarks, copyrights, patents, and other rights of ownership to images
and text used on the RF Cafe website are hereby acknowledged.
My Hobby Website:
one element matching - 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: one element matching Posted: Wed Aug 16, 2006
Joined: Fri Apr 21, 2006 10:34 pm
hi...if i have a parallel RC load (i.e. a BJT input impedance)
where R is almost 50 Ohms is it possible to use just a series inductor
to match to a 50 Ohm source? i can see how just using a shunt inductor
this can be accomplised but i'm not sure if using a series inductor
will do the match. if it can be done, can someone briefly explain how?
Post subject: Posted: Wed Aug
16, 2006 11:09 pm
Joined: Tue Apr 18, 2006 10:40
yes, you can do it. but it seems like you're mixing
up the definitions; if you know or found out that your IMPEDANCE is
something like 50-jXc, then that means that is 50 in series with Xc
and so when you do your analysis by hand or CAD you need to have a series
RC model and not parallel RC model.... of course, if you need to think
in parallel you can always convert to admittance. on the other hand,
if your admittance was 50-jXc then you're on the right track but this
value would be odd for a transistor because that means that your transistor
size is giving, in simple form, an rpi value of 1/50, which as far as
I can know can't be possible.