Electronics World articles Popular Electronics articles QST articles Radio & TV News articles Radio-Craft articles Radio-Electronics articles Short Wave Craft articles Wireless World articles Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs LinkedIn Crosswords Engineering Humor Kirt's Cogitations RF Engineering Quizzes Notable Quotes Calculators Education Engineering Magazine Articles Engineering software RF Cafe Archives RF Cascade Workbook 2018 RF Symbols for Visio - Word Advertising RF Cafe Forums Magazine Sponsor RF Cafe RF Electronics Symbols for Visio RF Electronics Symbols for Office Word RF Electronics Stencils for Visio Sponsor Links Saturday Evening Post NEETS EW Radar Handbook Microwave Museum About RF Cafe Aegis Power Systems Anritsu Alliance Test Equipment Amplifier Solutions Anatech Electronics Axiom Test Equipment Berkeley Nucleonics Bittele Centric RF Conduct RF Copper Mountain Technologies Empower RF everything RF Exodus Advanced Communications Innovative Power Products ISOTEC KR Filters Lotus Systems PCB Directory Rigol RF Superstore San Francisco Circuits Reactel RFCT TotalTemp Technologies Triad RF Systems Windfreak Technologies Withwave LadyBug Technologies Wireless Telecom Group Sponsorship Rates RF Cafe Software Resources Vintage Magazines Thank you for visiting RF Cafe!
PCB Directory (Manufacturers)

how to measure the S parameters of an unequal power divider? - RF Cafe Forums

RF Cafe Forums closed its virtual doors in 2010 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. 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.

NOTICE: The original RF Cafe Forum is available again for reading, and the new RF Cafe Blog is an active board.

-- Amateur Radio

-- Anecdotes, Gripes, & Humor

-- Antennas

-- CAE, CAD, & Software

-- Circuits & Components

-- Employment & Interviews

-- Miscellany

-- Swap Shop

-- Systems

-- Test & Measurement

-- Webmaster

 Post subject: how to measure the S parameters of an unequal power divider?
Posted: Thu Jun 18, 2009 8:46 pm 

Joined: Thu Jun 18, 2009 8:36 pm

Posts: 1

I have to measure the S-parameters of an unequal dual-band power divider using VNA. I have set Z0=50ohm during the calibration. The problem is the output impedences of the divider is different than 50 ohm. can I set the impedences of the two ports of the VNA seperately during the calibration? can anyone please help me about this?

 Post subject: Re: how to measure the S parameters of an unequal power divider?
Posted: Thu Jul 09, 2009 8:17 pm 

Joined: Wed Sep 10, 2008 5:49 pm

Posts: 4

Location: Central England

What springs to mind is this:

If you know the impedances that the O/P ports want to 'see' - i.e. what will match them, then a suitable resistive pad between the O/P under test and the 50-ohm input of the VNA will keep everything matched, thus enabling you to make the measurements. The unused port will need to be terminated in its appropriate R, for which you may - or may not - need a pad, depending on just what the O/P Z of that port actually is. Of course, you then need to correct the measurements (return loss, insertion loss, etc.) to take into account the attenuation of the pad(s). As for the pads themselves, you might have to make these yourself, and if the freqs. invloved are many tens of MHz, that could be difficult without introducing stray L and C, thus putting errors into your measurement. If, however, you have a 75-ohm to 50-ohm requirement, suitable coaxial pads are available commercially.




Quantum Mechanics - the dreams that Stuff is made of.

Posted  11/12/2012

everythingRF RF & Microwave Parts Database (h1) - RF Cafe
RF Superstore (RF Components) - RF Cafe
Windfreak Technologies Frequency Synthesizers - RF Cafe
Copper Mountain Technologies (VNA) - RF Cafe
Berkeley Nucleonics Corporation - RF Cafe

Please Support RF Cafe by purchasing my  ridiculously low−priced products, all of which I created.

These Are Available for Free


About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

Copyright: 1996 - 2024


    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 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: