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Altera_Forum's avatar
Altera_Forum
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15 years ago

phase difference 2 signals.

is possible whit fpga FFT or similar metod measure a phase difference from 2 PULSED-sinusoidals signals? the freq of signals is 60MHz but the duration of signals is 0.5uSEC, and the PRF of pu...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

My estimate is that it will detect phase difference across -180 ~ 180: 

    
              
ref: sin=0,1,0,-1            cos=1,0,-1,0   
              
sig: 0,1,0,-1                 re=0,1,0,1         im=0
      1,0,-1,0                 re=0                 im=1,0,1,0
       0,-1,0,1                re=0,-1,0,-1       im=0
      -1,0,1,0                 re=0                  im=-1,0,-1,0

Thus if you filter off the 120MHz(averaging) you get +dc or -dc of various values within +/-1