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Measuring Free Run LC VCO's Phase Noise (Read 3546 times)
neoflash
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Measuring Free Run LC VCO's Phase Noise
Mar 02nd, 2008, 3:24am
 
It seems difficult to measure free running LC-VCO's phase noise with E5052-A.

During measuring, it shows quick variation in low frequency band. Any experience with it?
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Ryan Cheung
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Re: Measuring Free Run LC VCO's Phase Noise
Reply #1 - Apr 30th, 2008, 8:43pm
 
If the measured VCO is biased from a regulator or something except a pin from the out-chip supply, it may encountered the problem you have mentioned. Based on my experience, there are 2 methods you can try:
1. tuning the IF gain of E5052 to a lower value;
2. using the 'supply voltage' of the E5052 to bias the VCO and adding a huge capacitor at the supply node if necessary.
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Miconos
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Re: Measuring Free Run LC VCO's Phase Noise
Reply #2 - Jun 29th, 2008, 12:17am
 
Give more details:
is it on Silicon?
how do you regulate and bias your VCO?
do you have a VCO buffer?
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