Sorry there are some problems.
Kindly refer to the below corrected question..........
Thank you

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Hello Everyone

I wish to clarify with you about the following topics  


If the input signal is coming in with two closely spaced channels, say at w  and  
w  + delta , then the third order IM terms of interest are  

2 w  - ( w  + delta  ) = w  - delta  

and  

2 ( w  + delta  ) - w  = w  + 2delta  

My question is, are both of these frequencies important for IM distortion, or is it only the first one, which is nearest to w  that causes problems ?  

For multitone input, say N tones, each spaced by delta , so that we have w , w  + delta ,  
w  + 2 delta , w  + 3 delta , ..., w  + N delta , we will get many 2 tone and 3 tone IM products  

2 (w  + i delta ) - ( w  + j delta  ) = w  + ( i - j ) delta  

and  

(w  + i delta ) + ( w  + j delta  ) - (w  + k delta ) = w  + ( i + j - k )delta .  

Are the only terms of interest for IM3 the ones where  

i - j = ± 1  

and  

i + j - k = ± 1 ?  

Thanks  

Jason and Tel