Hello!

How to mesure noise figure without noise generator on AD FMCOMMS2?

Hello!

How to mesure noise figure without noise generator on AD FMCOMMS2?

- 1 person found this helpful
You can use the gain method. For this measurement you need to know the gain, bandwidth and system characteristic impedance.

NF = Pn - (-174dBm/Hz + 10LOG10(BW) + GAIN)

To determine Pn you would terminate the input in characteristic impedance (50ohm) and measure Pn at the output.

The issue with this method is that it will be as accurate as the gain and BW numbers used.

- 1 person found this helpful
You would have to capture the data and do the computation in some other tool. To arrive at absolute signal levels you need to know that 0dBFS is 0.625Vpk.

Pn has units of dBm/Hz. In your case, once you perform the calculation in a certain bandwidth you will have power (Pncalc) in absolute units [dBm] provided you use 0dBFs = 0.625Vpk relationship). NF = Pncalc -174dBm/Hz - Gain

You can use the gain method. For this measurement you need to know the gain, bandwidth and system characteristic impedance.

NF = Pn - (-174dBm/Hz + 10LOG10(BW) + GAIN)

To determine Pn you would terminate the input in characteristic impedance (50ohm) and measure Pn at the output.

The issue with this method is that it will be as accurate as the gain and BW numbers used.