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Multitone IMD - RF Cafe Forums
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ljoseph Post subject: Multitone IMD Posted: Fri Oct 02, 2009 3:58
pm
Captain
Joined: Tue Sep 04, 2007 7:54 am Posts:
13 Location: Dallas Hi,
This is about IM calculations
in case of multitone.
For example take an amplifier with OPI3
of 18.1dBm, gain =11 dB. Two tone IM is 58.2 dBc. Input is -19 dBm
Output = -19+11 = -8 dBm. IM = 2(18.1-(-8))+6 = 58.2dBc
Now,
I am driving this amplifier with 15 tones each having an input power
of -19-10*log(15)=-30.8dBm Total output power for 15 input tones
= -8 dBm. What will be the worst case IM in dBC with respect to -8dBm
of total output power?
Top
Kirt Blattenberger
Post subject: Re: Multitone IMDPosted: Fri Oct 09, 2009 3:32 pm
Site Admin
Joined: Sun Aug 03, 2003 2:02 pm Posts:
308 Location: Erie, PA Greetings ljoseph:
The link I used
to have for a paper titled "A General Algorithm to Calculate Third Order
Intermodulation Product Locations for any Number of Tones," by Chris
Arnott, has disappeared from it's location on the CED website. So, I
just scanned in and OCRed a copy provided to me by Chris back when I
worked with him at RF Micro Devices. You can access it here:
http://www.rfcafe.com/references/electrical/calculate-imd-any-number-tones.htm
Hopefully that will get you where you're going.
_________________
- Kirt Blattenberger RF Cafe Progenitor & Webmaster
Posted 11/12/2012
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