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Altera_Forum
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15 years ago

How to determine if 2 signals are in quadrature

Hello friends, I need to determine if two signals are precisely on 90 deg. phase. In fact, there is a xor phase comparator and I try to catch lock condition as indicator (for viewing purposes, ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Xor will help detection of phase difference but can't measure actual difference.

If your signals are two sine waves (sine/cos) and known frequency then try this simple idea:

delay one signal one sample at a time until both are equal in phase as indicated by xor and measure your delay relative to frequency to see if it is 1/4 cycle or 3/4 cycle