Formulas & Data:
- Electronics
- Mathematics
- Physics
- RF & Microwaves

Parts Vendors:
- all hand-selected

- Amateur Radio
- Vintage Articles:
- Electronics World
- Popular Electronics
- Radio & TV News
- Radio Craft
- Short Wave Craft
- Wireless World

- Events Calendar
RF Cafe Homepage
Copyright 1999-2015   •−•  ••−•    −•−•  •−  ••−•  •   "RF Cafe" in Morse Code  >> Listen to It <<
- EW & Radar Handbook
- Quizzes       - Software
- App Notes
- Calculators
- Advertise on RF Cafe
- About RF Cafe™
- RF Cafe Shirts & Mugs
- RF Cafe Archives
RF Cafe Book Contest
- RF Cafe on Visit RF Cafe on Facebook Visit RF Cafe on Twitter Visit RF Cafe on LinkedIn
- Tech Humor
- Forums Archive
- Job Board
- Donate to RF Cafe
- Kirt's Cogitations
Custom Search
More than 10,000 searchable pages indexed.
Greetings: There is so much good stuff on RF Cafe that there is no way to list or link to all of it here. Please use the Search box or the Site Map to find what you want - there is a good chance I have it here. Thanks!

microstrip feed line - 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.

 Post subject: microstrip feed line
Posted: Thu Dec 29, 2005 6:11 pm 

Joined: Mon Nov 21, 2005 3:30 pm
Posts: 1
Dear freinds,
i ask you why the almost microstrip line used as the feed line for the patch antenna are 50 Ohm? i ask you also if we can use other 74 Ohm feed line excitation for this antenna?
thanks for your help....

 Post subject:
Posted: Fri Dec 30, 2005 10:27 am 

Joined: Thu Jul 28, 2005 6:18 pm
Posts: 3
If your antenna impedance is 50 ohms, you'll want to feed it with a 50 ohm microstip line or you'll have some mismatch loss reducing the efficiency of your antenna. Another reason to use 50 ohms is that, presumably, at some point you're going to solder some type of coax or coaxial connector to the microstrip. The majority (if not all) of the cables and connectors used for this purpose are 50 ohms.

Now, you could certainly feed the antenna with a 74 ohm microstrip line, but you would have to design the patch to have an impedance of 74 ohms. This isn't the convention and I've never done it that way so I can't tell you how feasible it is.

 Post subject:
Posted: Fri Dec 30, 2005 5:55 pm 
thanks, so please can you tell me how we can determine the input impedance for the UWB antenna, so here we have a broad band frequency, and we know that the input impedance is calculated for a single frequecy. i ask you please to explain me this problem & send me if you have some theoretical doc. thank you very much
happy new year for you and for all our freinds on the rfcafe forum...

Posted  11/12/2012

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