Because of the high maintenance needed to monitor and filter spammers from the RF Cafe Forums, I decided that it would
be best to just archive the pages to make all the good information posted in the past available for review. It is unfortunate
that the scumbags of the world ruin an otherwise useful venue for people wanting to exchanged useful ideas and views.
It seems that the more formal social media like Facebook pretty much dominate this kind of venue anymore anyway, so if
you would like to post something on RF Cafe's
page, please do.
Below are all of the forum threads, including all
the responses to the original posts.
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)