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:
microstrip BP filter from an elliptic prototype - 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: microstrip BP filter from an elliptic prototype
Posted: Sat Dec 31, 2005 8:20 am
Aug 14, 2005 3:24 pm
I should design a narrow band BP filter on microstrip in s band.
the requiered degree of the filtr using chebyshev prototype is 21 but
using elliptic is just 7. but I can't find a systematic way to depart
from this elliptic LP prototype to a BP common filtr type on microstrip.
All I found is for all-pole filtrs not for an elliptic type.
may anyone help?
Post subject: Posted:
Sat Dec 31, 2005 9:51 am
Joined: Mon Jun
27, 2005 2:02 pm
In general you reach to any type of filter from the LP prototype
by using the Koruda transformations. To transfer to microstrip from
lumped elements you will have to use Richards transformations.
Nowadays you can use a simulation tool which does all this work
for you and provides you with pretty accurate results. You will need
to use both linear simulation to tune your microstrip length and width
and coupling between the resonators and also to use an EM simulation
to see how the filter performs inside walls.
My preferred choice
would be Eagleware GENESYS (Now part of Agilent). This tool has synthesis
functoins for lumped and distributed filters in which you can define
the topology, required attenuation etc and get a circuit schmeatic including
values. It also has an EM simulation capability.
Post subject: Microstrip Elliptic-function filtersPosted:
Sat Dec 31, 2005 7:48 pm
Just a small point: If you google for the
transformations, you need to type in "Kuroda" not "Korodah".
Post subject: Posted: Sat Dec
31, 2005 10:03 pm
Joined: Mon Jun 27,
2005 2:02 pm
Thanks for the correction
guest. It should be Kuroda.
For you eastern here is a link to
an application note that may be useful: