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:
LNA Help!!! - 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: LNA Help!!!
Unread postPosted: Thu Jul
14, 2005 10:27 am
Joined: Mon May 30,
2005 9:16 am
I'm a gilr who isn't able to design a LNA
for ZigBee application at University.The constraints are: Vcc = 1.8V,
frequency = 915MHz NF lower as possible,power consumption as well .
Could you give me the formulas and one simple (single ended input, differential
output) circiut. Please could you give me any suggestions ? I really
Thu Jul 14, 2005 10:49 am
Joined: Mon Jun 27, 2005 2:02 pm
First of all, you will need to select a transistor
matching for your frequency band and gain.
There are plenty of
formulas to use when you design an LNA: Stability, Gain, Return Loss,
Noise Figure etc. Nowadays, Engineers mostly use CAE (Computer Aided
Engineering) tools for designing LNA, Filter and other RF circuits.
All of these formulas are entered into the design tool and by that save
the designer lot of time and calculations.
Attached is a link
to a PDF that will certainly give you a good staring point to design
your LNA (It includes a discussion about the design and formulas involved
in LNA design):
http://www.odyseus.nildram.co.uk/RFMicr ... torial.pdf
Should you need additional help, please let me know.
Thu Jul 14, 2005 11:41 am
Firstly, I have to
thank you, I'm reading your link and I think it will be useful.
Secondly, I have to use a CMOS or TSMC 0.18um tecnology, input matching
50 ohm. Do you have any documents about CMOS LNA?
is possible to show a circiut in the topic reply without to have a web
Thank you again