Hi,

I have a frequency mixer LT5511 (http://cds.linear.com/docs/en/datasheet/5511f.pdf). At the output of the mixer (RF output), the power should be 4 dBm. I would like to calculate the power level at the mixer's inputs.

I am not sure which parameters from the datasheet do I need, for exemple do I need for that the minimum power that the mixer needs, noise figure, IIP3, conversion power gain…. to find the power's at each of the mixer's inputs ( IF and LO)? And would the power at each of the 2 inputs (IF and LO) be the same or different ?

So I am asking for some help to find them ?

Thank you

 

Here's a start for you:
http://rfic.eecs.berkeley.edu/~niknejad/ee242/pdf/ee242_mixer_fund.pdf
" Conversion Gain: Ratio of voltage (power) at output
frequency to input voltage (power) at input frequency
 Downconversion: RF power / IF power
 Up-conversion: IF power / RF power"

 

Here's a start for you:
http://rfic.eecs.berkeley.edu/~niknejad/ee242/pdf/ee242_mixer_fund.pdf
" Conversion Gain: Ratio of voltage (power) at output
frequency to input voltage (power) at input frequency
 Downconversion: RF power / IF power
 Up-conversion: IF power / RF power"

It's not what I am looking for. We don't need to do integrals and all that stuff to find the input's power.It's supposed to be much simpler that that when we have the datasheet and the output power....

 

Exactly.
The conversion gain, given in the datasheet, is the ratio of the power at the output to the power at the input. The conversion gain given in the datasheet for the LT5511 is 0dB. That means that the output power is equal to input power. it really couldn't be simpler. Where do integrals come into that?

 

Exactly.
The conversion gain, given in the datasheet, is the ratio of the power at the output to the power at the input. The conversion gain given in the datasheet for the LT5511 is 0dB. That means that the output power is equal to input power. it really couldn't be simpler. Where do integrals come into that?

But I have 2 inputs IF and LO. Are their's power levels, both equal to RF output power level?

I saw integrals at the power's formulas in the pdf you sent.

 

Again, from the datasheet:

So it could be anywhere between those values and work correctly. The LO level, as long is it is in the correct range, does not significantly affect the output amplitude.