Multitone IMD - RF Cafe Forums
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Below are all of the forum threads, including all the responses to the original posts.
Post subject: Multitone IMD Posted: Fri Oct 02, 2009 3:58 pm
Joined: Tue Sep 04, 2007 7:54 am
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?
Post subject: Re: Multitone IMDPosted: Fri Oct 09, 2009 3:32 pm
Joined: Sun Aug 03, 2003 2:02 pm
Location: Erie, PA
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:
Hopefully that will get you where you're going.
- Kirt Blattenberger
RF Cafe Progenitor & Webmaster