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!
Amplifier Solutions Corporation (ASC) - RF Cafe

Measure tuner loss in matching circuit - 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

sos

Post subject: Measure tuner loss in matching circuit Posted: Thu Aug 04, 2005 7:55 pm

Can anyone explain to me the most accurate way to measure the tuner insertion loss in a matching network...Thank you

Top

Guest

Post subject: Posted: Fri Aug 05, 2005 8:51 am

Are you really looking for the most accurate way?

What are you calling a tuner? A parallel open circuit or short circuit stub on a PCB?

If this is the case I suggest you cascade the network with an impedance inverting length of transmission line in between and re-resonate the matching network to 50 ohms. When you match back to 50 ohms (only one frequency unfortunately), you get a system which have the insertion loss of the 2 times the tuner, plus a quater wave line that you can easily remove from the loss also.

This way a VNA measurement will give you the results.

Top

sos

Post subject: Posted: Fri Aug 05, 2005 11:05 am

There is NO accurate way to measure the insertion loss of the slug tuner after it tuned to optimize for best performance in a matching network. However, if you can explain a better measurement method to measure the slug tuner loss after it tuned to a certain impedance. A suggestion is to put a 50 ohm line in series with the tuner which measure the total loss of resistive loss + load mismatch loss. This idea still questionable because the tuner is not 50 ohm. Then, this measurement is NOT valid. May I repeat the case: I have to measure the insertion loss of a slug tuner after it been tuned to optimize for best performance in a matching network.

Thank you

Top

Drew T.

Post subject: Posted: Fri Aug 05, 2005 11:17 am

If your frequency is within the BW of an available oscilloscope, you can always probe the voltage at the input and at the out of the tuner and get a ratio. Insert a Tee at both ends of the tuner to probe. Of course, there will be some abiguity due to the Tees, but you can probably then add back in the measured IL of the Tees. How exact are you looking to be?

Top

sos

Post subject: Posted: Fri Aug 05, 2005 4:01 pm

The slug tuner is connected to the output loadline, so the impedance transformation at that connection is NOT 50 ohm. Therefore, we cannot measure the exact insertion loss with the VNA, because the VNA is the 50 ohms system. How accurate? I guessed that there is NONE, but better estimate measure technique is what I am trying to understand...What do you think about use another tuner to tune the conjugate impedance of the first tuner? Now, we got 50 ohm system...The question is How do we determine the real loss of the first tuner? Any thought?

Top

Guest

Post subject: Posted: Fri Aug 05, 2005 5:14 pm

It is 50% of the total loss.

Top

sos

Post subject: Posted: Sat Aug 06, 2005 3:32 am

cool...that is what I thought...May take the total divide by 2 then...thanks guys

Posted  11/12/2012

Boonton RF Power Measurement
Anritsu Test Equipment - RF Cafe
Windfreak Technologies Frequency Synthesizers - RF Cafe
ConductRF Phased Matched RF Cables - 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

Webmaster:

    Kirt Blattenberger,

    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:

AirplanesAndRockets.com