[time-nuts] Best phase detector / mixer for 100MHz?

[Adrian]

Bruce Griffiths schrieb:
> Support HpW-Works.com wrote:
>> Bruce,
>>
>>>> There's no evidence of a cross power spectrum function in this suite.
>>>> One needs to be able to average at least 10,000 cross power spectra 
>>>> for some
>>>> applications.
>> In the PSD (power density)&  PSP (power spectrum) there are cross 
>> power and cross
>> power complex average implemented (selectable using the spectrum 
>> channel mixer)!
>> Additional to this you may apply / add averaging of the resulting 
>> spectrum or use
>> additional peak hold.
>>
>> Average of 10'000 cross points is a large count and often seen on 
>> 1-4k sample size.
>> Better in my opinion is to use a higher sample size 32k-64k and then 
>> less averaging
>> is required.
> The equivalent phase noise (measured in dBc/Hz) is essentially 
> independent of the sample size.
> So increasing the sample size isnt particularly useful for reducing 
> the phase noise floor.
> The increased frequency resolution achieved by increasing the sample 
> size is only useful for measuring spurs.
> In the direct digital method of measuring phase noise a few 
> terasamples (a few gigasamples at baseband) need to be processed to 
> achieve a sufficiently low instrument noise floor.
> However with a sound card plus a mixer a somewhat lower number of 
> samples should suffice since there is no carrier.
>> Just download the evaluation version with fully feature set.
>>
>> HpW
>>
>>
> Bruce
>
>
A HP/Agilent VEE based solution would be much more flexible. There is a 
sound card driver available.
I just didn't get deep enough into digital signal processing before the 
3562A came...

Adrian

> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>