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:
Dual-Gate MOSFET - 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: Dual-Gate MOSFET Posted: Sat Nov 11, 2006 9:32
Joined: Thu Aug 10, 2006 7:09 pm
Hello everyone. I was wondering if you can help me set up a simple
circuit to utilize the BF988 dual-gate MOSFET as a switch to pass on
(or prevent the passing of) a 315MHz sine signal. I was thinking of
inputting the 315 MHz signal into one gate and the control (ON/OFF)
signal into the other gate. Would that work. Your advice and suggestions
would be greatly appreciated. Thanks.
Post subject: Posted: Sun Nov 12, 2006 4:42 am
Joined: Mon Jun 27, 2005 2:02 pm
This looks like a good idea.
assure that the level of the control signal is much higher than the
315MHz RF signal. Looking at the curve of Gain vs Vgs1 voltage in page
5 of the data sheet, shows how much the signal would be amplified or
attenuated. The gain response over the Vgs1 voltage variation looks
flat with some peaks.
I would however also consider another
circuit: Why not using an RF switch?
Posted: Thu May 03, 2007 5:17 am
May 03, 2007 2:55 am
yeah RF switch
will give good performance ,
also check NXP they produce some MOSFETS
and Switches for RF