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

Phase/Magnitude Detector - 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.


eeboy
Post subject: Phase/Magnitude Detector Posted: Sun Oct 14, 2007 10:41 am

Lieutenant


Joined: Sun Oct 14, 2007 10:35 am
Posts: 2
Hello,

I am looking for a simple phase magnitude circuit. I have a few references which have a straight forward solution for obtaining the magnitude but the phase seems to be overly complicated (involving a diode ring modulator).

Any suggestions?

Thanks,
Jason


Top

nubbage
Post subject: Posted: Tue Oct 16, 2007 3:57 am

General


Joined: Fri Feb 17, 2006 12:07 pm
Posts: 218
Location: London UK
Hi eeboy
If you can down-convert the channels to HF (maybe the signal frequency is already <50MHz?) then an XOR logic followed by an integrator will measure phase fairly accurately. With the two channels squared off to logic levels and fed to a 74LS exclusive OR, the output will contain a narrow spike when the channels are in phase, and will be a logic 1 when they are 180 out of phase. Any in-between state gives a pulse whose width is proportional to the phase difference. The integrator is a pulse width to analog level low-pass filter.


Top

eeboy
Post subject: Posted: Tue Oct 16, 2007 4:34 am

Lieutenant


Joined: Sun Oct 14, 2007 10:35 am
Posts: 2
That's a beatiful solution... very simple!

One more issue though... this would give a good indication as to when the phase angle is zero however, it does not give an indication as to wether it's lagging or leading. I can't think of an easy method to accomplish this. I could always calculate the time between the voltage and current peak but this becomes not trivial. Any suggestions?

FYI, the frequency is 27MHz.

Thanks!







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
    KB3UON

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