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!

IQ Phase Error and Image Rejection - 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: IQ phase Error and Image rejection Posted: Tue Sep 12, 2006 12:06 pm


Joined: Fri Feb 11, 2005 6:32 am
Posts: 4
hello guys,

two questions:

I have a device (Zero-IF) and an analyzer with IQ inputs , I'd like to measure- the image rejection. How can I do it?

-what is the relation between IQerror and image rejection??



Post subject: Posted: Tue Jul 10, 2007 10:53 am


Joined: Tue Jun 26, 2007 10:27 am
Posts: 11
Location: Dallas, TX
Hi wallace0075,

For Image Rejection you may need to do a basic theoretical analysis. You can set up a basic block diagram (signal flow diagram) for an I/Q receiver. Add some gain mismatch in one path and add some phase mismatch to the LO path. Then, sum up the outputs of the I and Q paths (you can take the difference also, and get the same relationship) so that you end up with a SSB response at the output.

Your expression will then contain an expression for the desired frequency and for the sideband frequency. You then take the powers of the desired and undesired and take the quotient. This will then give you an expression for SBRR based on amplitude and phase mismatch.

An example of this can be found here: ... mber=33037
Hope this helps!


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 !