Thank you for visiting RF Cafe! Electronics World Cover,TOC,and list of posted Popular Electronics articles QST Radio & TV News Radio-Craft Radio-Electronics Short Wave Craft Wireless World About RF Cafe RF Cafe Homepage RF Cafe in Morse Code Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs Twitter LinkedIn Crosswords Engineering Humor Kirt's Cogitations Engineering Event Calendar RF Engineering Quizzes AN/MPN-14 Radar 5CCG Notable Quotes App Notes Calculators Education Magazines Software,T-Shirts,Coffee Mugs Articles - submitted by RF Cafe visitors Simulators Technical Writings RF Cafe Archives Test Notes Wireless System Designer RF Stencils for Visio Shapes for Word Search RF Cafe Sitemap Advertising Facebook RF Cafe Forums RF Cafe Homepage Thank you for visiting RF Cafe!

Printed Antenna - RF Cafe Forums

The original RF Cafe Forums were shut down in late 2012 due to maintenance issues. Original posts:

Amateur Radio | Antennas | Circuits & Components | Systems | Test & Measurement

 Post subject: printed antenna
Posted: Fri Jun 11, 2004 2:23 pm 

Joined: Fri Jun 11, 2004 2:17 pm
Posts: 5
I am fairly new into antenna design as I have been mainly a RF guy for 4 years working on TX and RX circuits for cellular products and have ventured into the 2.4GHZ area now.

Question is I am trying to figure out the main advantages of having an antenna at 200ohms versus a 50ohm for 2.4Ghz.

From the tx or rx path I have a balun that converts the signal from 50ohm to 200ohm (this is from previous designer who left and i took over and he is overi n japan now). I have worked with cellular antenna and have always matched to 50ohms, just curiuos why for a 2.4GHz antenna it would be 200ohms.

any insight on starting this desing would be greatful as I am the only RF guy here and I am getting some antenna design books next week. Thanks for responses.

 Post subject:
Posted: Fri Jun 11, 2004 2:51 pm 
The only reason that I can come up with is... that impedance (200 ohms) is just what that specific antenna type looks like. As you know, not all antennas are 50 ohms driving impedance, infact most arent, so you have to match to them. It just turns out that some standard kinds of antennas, like monopoles have a pretty low impedance to start with and can be used in 50 ohm systems without matching. Some patch antennas can look like 200 ohms due to the physics of the antenna.

In other words, there is no advantage to having a 200 ohm termination impedance specifically, but the antenna impedance is more driven by the type antenna and what kind of performance you need from an antenna pattern point of view. Matching is often secondary.

If you have a resistive 200 ohms, then consider yourself lucky, that's an easy match.

Good luck,


 Post subject: thanks
Posted: Fri Jun 11, 2004 5:50 pm 

Joined: Fri Jun 11, 2004 2:17 pm
Posts: 5
thanks for the insight, I had the feeling that was the reasoning, just was not sure.

I appreciate the quick response.

 Post subject:
Posted: Wed Jul 07, 2004 3:05 pm 
Also, just to add to the excellent comments, most antennas if not all, have reactance so the actaul impedance you are considering needs to take into account R + jX for matching to your system or calculating radiated power. If X is not minimized then radiated power is reduced. Of course there are other variables to consider in antenna design.

Posted  11/12/2012

RF Cafe Software

   Wireless System Designer - RF Cafe
Wireless System Designer

RF & EE Symbols Word
RF Stencils for Visio
Calculator Workbook
RF Workbench
Smith Chartâ„¢ for Visio
Smith Chartâ„¢ for Excel

About RF Cafe

Kirt Blattenberger - RF Cafe WebmasterCopyright
1996 - 2022
Kirt Blattenberger,

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 Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...

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:

Try Using SEARCH
to Find What You Need. 
There are 1,000s of Pages Indexed on RF Cafe !