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:
Gap between the Microstip trace and ground trace - 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: Gap between the Microstip trace and
Unread postPosted: Fri Jan 14, 2005 5:27 am
If 'W' is the width of the microstrip line, maintaining a gap of 'W'
between the microstrip line and ground trace/plane next to it on the
same layer is considered as good RF practice. Am I right on this thumb
If anyone has opinion on this , pl let me know. Let me
know even if you agree on it. I am following this thumb rule in the
RF board I am making. It will greatly aid in coming out with good board
with your valuable opinions.
subject: Microstrip Line width
Unread postPosted: Fri Jan 14, 2005
The rule of thumb is correct but remember it is a rule
of thunb. The width is what determines the impedance of the line so
I would recommend going on the Microsoft Office Website and downloading
there "free" transmission line calculator. I am sure Kirt has a link
to the sight. In this way you will know for a fact that you have the
proper impedance. Keeping the ground trace a W away from the ground
trace is usually adequate but I usually keep it 2W away.
Unread postPosted: Fri Jan 14,
2005 11:39 am
Yes it is a good practice. I did it in my latest
board design and will be doing it in the next too.
Post subject: Re: Microstrip Line
Unread postPosted: Fri Jan 14, 2005 12:16 pm
Joined: Sun Aug 03, 2003 2:02 pm
Location: Erie, PA
recommend going on the Microsoft Office Website and downloading there
"free" transmission line calculator. I am sure Kirt has a link to the
Right you are. There is a link to it (Tx-Line
is the applet name) on the Software page (1) and the Calculators page
(2), and the direct link to the MWO site is here (3). It is quite a
nice program for free!
- Kirt Blattenberger :smt024
Mon Jan 17, 2005 3:55 am
Please make sure that GND away from
the Transmission Line (At least 3 to 4 times of the width due to the
GND coupling effects if it is filter / high power applications).
Or make use of Coplanar Waveguide with GND plane, which is very
similar to the Microstrip but it has lots of advantages.
Please check Microstrip Vs Coplanar Waveguides (with GND plane)