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
page, please do.
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
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
I am driving this amplifier with 15 tones each having an input power
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