How to compress AC output Vpp for pulse power detector?

[tony_lth]

We use Mini ZX47-40+ for pulse power detector.
Conditions: carrier freq 2G, pulse period 2us, pulse width 1us
Config: ZX47-40+ output to the input of ADC, then sampled by controller CPU
Problem: The power detector slope is -25mV/dB. But the datasheet said at the detector output there is 20mV Vpp typical at 10MHz. At the oscilloscope, we can see the power detector output fluctuate about 10mV, sometimes about 20mV, that can cause output power varies 0.8dB and is not accpeted. How to compress the fluctuation to within 2mV?:shock:

 

[jmpac]

I think you cannot compress the fluctuation. Furthermore, the datasheet is giving you the dynamic range at +/- 1dB error. What's the resolution of your ADC (milivolts per bit)?

 

[BigBoss]

If ADC resolution is greater than 20mV ( low resolution ADC ) in this case fluctuation can not be sensed by ADC but the overall accuracy will be low as well...