When measuring NoiseFigure of VGA HMC960 I've got values that don't match with Datasheet.
Measured NF slightly depends on prorammable Zin, bias settings (standart or high linearity) and type of power supply source (pulse or analog)
NF is calculated as (Zin HMC960 = 100 Ohm diff) :
NF = [Measured Noise Density (dBm/Hz)] + 174 dBm/Hz (Noise Floor) - Gain + 3 dB
*3 dB is due to using only half out power.
Could you, please, help me to understand whats wrong with measurement? Why measured NF don't match with Datasheet ?
How to correct measure Noise Figure of this VGA ?