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Message ID: 3552     Entry time: Thu Sep 9 12:02:03 2010
Author: Alberto 
Type: Update 
Category: Electronics 
Subject: Frequency Generation Box - Amplitude Noise Measurements 

I measured the amplitude noise of the source outputs and the EOM outputs of the Frequency Generation box.

the setup I used is shown in this diagram:

FreqBoxAmplitudeNoiseMeasurementSetup.png

(NB It's important that the cables from the splitter to the RF and LO inputs of the mixers are the same length).

The results of the measurements are shown in the following plot:

 FreqBoxAmplitudeNoise_BusbyBox_AllChannels.png

Considerations:

1) both Crystals (29.5MHz and 11MHz) have the same noise

2) the 55MHz source's noise is bigger than the 11 MHz (~2x): the frequency multiplication and amplification that happen before it, add extra noise

3) the noise at EOM outputs is ~2x bigger than that of the relative sources

 

When I have the chance, I'll plot the results of my calculations of expected noise and compare them with the measurements.

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