looking for instrument that can do 2 channel phase comparison

bulegoge · 2014-10-31T15:00:07+00:00

I need to compare the phase difference of two signals at 1ghz. The signal s are pulsed at 500 ns width. The two signals come from the same base freq uency device so they are coherent but at an unknown phase relative to each other. I can build a two down converters with minicircuit parts and compar e their phases ate say 10 mhz on a scope. But i am in a hurry and need to know if there is a commercially available instrument which i can do the sam e thing with?

Oct 31, 2014 25 Replies

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John S 11 years ago

Thanks! So that confirms my calcs.

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Tim Wescott 11 years ago

Aw crap -- I slipped a digit. I always take the time to double-check my calculations on a calculator or math package when I'm getting paid for it, but not always when it's a newsgroup question...

200mm in coax that has the close-to-typical 2/3 velocity factor that makes the math easy. Whatever 200mm / 360 degrees is, that's how many mm/ degree.

www.wescottdesign.com

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Tim Wescott 11 years ago

In free space, yes. Coax velocity factor is enough lower than unity that you have to take it into account.

www.wescottdesign.com

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djlocher56 11 years ago

Thanks for taking time to make an answer. I knew you had the number off, but the gist of what you were trying to say was more about i/q processing.

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josephkk 11 years ago

there on

good

degree.

Yup. i made hash of my arithmetic right from the start.

?-)

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Jasen Betts 11 years ago

Probably less, dependant on velocity factor.

298mm / 360 degress * velocity_factor,

umop apisdn

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