Homepage - RF Cafe
Webmaster: Kirt Blattenberger | KB3UON | Sitemap | ©1996-2014
Menu below is just a small sample of what is here!
Custom Search
More than 10,000 searchable pages indexed.
•−•  ••−•    −•−•  •−  ••−•  •
RF Cafe Morse Code >Hear It<

IQ phase Error and Image rejection - RF Cafe Forums

Because of the high maintenance needed to monitor and filter spammers from the RF Cafe Forums, I decided that it would be best to just archive the pages to make all the good information posted in the past available for review. It is unfortunate that the scumbags of the world ruin an otherwise useful venue for people wanting to exchanged useful ideas and views. It seems that the more formal social media like Facebook pretty much dominate this kind of venue anymore anyway, so if you would like to post something on RF Cafe's Facebook page, please do.

Below are all of the forum threads, including all the responses to the original posts.

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:
http://ieeexplore.ieee.org.ezproxy.tamu ... mber=33037
Hope this helps!


Posted  11/12/2012
A Disruptive Web Presence

Custom Search
Over 10,000 pages indexed! (none duped or pirated)

Read About RF Cafe
Webmaster: Kirt Blattenberger

RF Cafe Software

RF Cascade Workbook
RF Cascade Workbook is a very extensive system cascaded component Excel workbook that includes the standard Gain, NF, IP2, IP3, Psat calculations, input & output VSWR, noise BW, min/max tolerance, DC power cauculations, graphing of all RF parameters, and has a graphical block diagram tool. An extensive User's Guide is also included. - Only $35.
RF system analysis including
frequency conversion & filters

RF & EE Symbols Word
RF Stencils for Visio

Product & Service Directory
Personally Selected Manufacturers
RF Cafe T-Shirts & Mugs

RF Cafe Software

Calculator Workbook
RF Workbench
Smith Chart™ for Visio
Smith Chart™ for Excel
Your RF Cafe Progenitor & Webmaster
Click here to read about RF CafeKirt Blattenberger... single-handedly redefining what an
                                 engineering website should be.

View the YouTube RF Cafe Intro Video Carpe Diem! (Seize the Day!)

5CCG (5th MOB): My USAF radar shop

Airplanes and Rockets: My personal hobby website

Equine Kingdom: My daughter Sally's horse riding website