•−•  ••−•    −•−•  •−  ••−•  •
RF Cafe Morse Code >Hear It<

Job Board

About RF Cafe™

Sitemap

microstrip BP filter from an elliptic prototype - RF Cafe Forums

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 Facebook page, please do.

Below are all of the forum threads, including all the responses to the original posts.


eastern
Post subject: microstrip BP filter from an elliptic prototype Posted: Sat Dec 31, 2005 8:20 am

Lieutenant

Joined: Sun Aug 14, 2005 3:24 pm
Posts: 2
Location: iran
Hi everybody

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?


Top

IR
Post subject: Posted: Sat Dec 31, 2005 9:51 am

Site Admin


Joined: Mon Jun 27, 2005 2:02 pm
Posts: 373
Location: Germany
Hello eastern,

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.

Good Luck!

_________________
Best regards,

- IR


Top

Guest
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".

Good Luck!


Top

IR
Post subject: Posted: Sat Dec 31, 2005 10:03 pm

Site Admin


Joined: Mon Jun 27, 2005 2:02 pm
Posts: 373
Location: Germany
Thanks for the correction guest. It should be Kuroda.

For you eastern here is a link to an application note that may be useful:

http://home.sandiego.edu/~ekim/e194rfs01/filterek.pdf

_________________
Best regards,

- IR



Posted  11/12/2012
Custom Search
More than 10,000 searchable pages indexed.

Your RF Cafe
Progenitor & Webmaster

Click here to read about RF CafeKirt Blattenberger... single-handedly redefining what an engineering website should be.

View the YouTube RF Cafe Intro Video Carpe Diem!
(Seize the Day!)

5th MOB: My USAF radar shop

Airplanes and Rockets: My personal hobby website

Equine Kingdom: My daughter Sally's horse riding website