up-conversion mixer output 3rd-order intercept point setting is correct?

[wccheng]

Dear all,

I have a question about the output 3rd-order intercept point simulation frequency setting in up-conversion mixer. I hope anyone could correct me if I am wrong.

For example, my upmixer is with input IF, input LO and output RF.

For 1dB compression point simulation, I will give input IF=10MHz, input LO=1000MHz. Then I measure the output RF=1010MHz.

If I wanted to simulate the output 3rd-order intercept point, my this frequency setting was correct or not?
I will give input IF= 9MHz and 11MHz, input LO=1000MHz. Then I measure the main tone RF frequency=1011MHz and 3rd-order tone=1007MHz. Am I correct?

Thanks,

wccheng

 

[tony_lth]

I think 3rd-tone should be the higher of 1007M and 1013M.

 

[luckyali]

if u apply two frequencies eg 9 MHz & 11 MHz (spaced by 2MHz) then the intermodulation products are at multiples of 2MHz.

SO, 2MHz below 9MHz and 2MHz above the 11MHz carrier will be the 3rd Order intermodulation products (IM3)
i.e at 7MHz and 13MHz.
and again 2MHz below and above the IM3 will the IM5 products.