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!
RF Electronics Shapes, Stencils for Office, Visio by RF Cafe

Error in ADS - 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: Error in ADS Posted: Tue May 02, 2006 5:05 am


Joined: Tue May 02, 2006 4:59 am

Posts: 15

I use the Budget tool and got that error message :

[b]Error detected by HPEESOFSIM during Budget Analysis `Budget'.

Term3: ERROR: During Budget cascaded noise analysis; possible element with

unrealistic S-parameters; look for |S11| > .8; |S22| > .8; |S12| near, equal

or greater than |S21|. [/b]

Maybe anyone understand it ?

I know its depend on the attenuators location but im not understand why .



Post subject: ADS error messagePosted: Tue May 02, 2006 6:32 pm


Joined: Wed Feb 22, 2006 3:51 pm

Posts: 104


That's actually a more-helpful error message than many, because it tells you what to look for in your design. Unfortunately it's not very specific - it doesn't tell you where to look, and it gives 3 alternatives.

The S11 and S22 checks say that maybe there's a severe impedance mismatch between two stages, the S12/S21 message says that maybe there's a large amount of (unexpected/undesired) feedback around an active stage.

Good Luck!



Post subject: Posted: Tue May 02, 2006 10:03 pm

Site Admin

Joined: Mon Jun 27, 2005 2:02 pm

Posts: 373

Location: Germany


I took the initiative and replied to this post directly by email as we had already a brief correspondence in the past. I mentioned that the main cause of such a problem is instability (As fred47 mentioned), this is also noticed by the values of S11, S22 which are greater than 1. This is likely to be caused by poor matching. I also suggest you to do the budget analysis simulation step by step from the start: Block after block. And to see in which step the error message displays. By doing that you can find out the problemtaic element and check it separately.

Good luck!


Best regards,

- IR

Posted  11/12/2012

Exodus Advanced Communications Best in Class RF Amplifier SSPAs
Anritsu Test Equipment - RF Cafe
RF Cascade Workbook 2018 by RF Cafe
Holzworth RF Synthesizers
Innovative Power Products Passive RF Products - 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: