for one section of my project, i need to know the phase difference between two signal.(adsbygoogle = window.adsbygoogle || []).push({});

they are both 40MHz, but out of phase by a certain angle.

i have a AD8333 board from Analog Devices,

it is a dual I/Q demodulator consist of double-balanced gilbert cell mixers.

The board has 2 RF inputs, a LO input, and 4 output (I1, I2, Q1, Q2).

I have an oscilloscope to display the results.

according to wikipedia http://en.wikipedia.org/wiki/Phase_detector#Analog_phase_detector

there is a way to measure the phase difference using IQ demoludator.

in this post, https://www.physicsforums.com/showthread.php?t=336619

f95toli mentioned that:

the magnitude is just given by the norm (sqrt(I^2+Q^2)) and the phase by the phase angle (arctan I/Q)

So is this method bellow correct?

to get the phase difference of both my RF signal,

i put one the signal into RF input1, and the second signal into the LO,

then i display both the I1, and Q1 in the oscilloscope, and get an get the peak to peak magniture for both the I1 and Q1, then calculate arctan I1/Q1, to get the phase difference?

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# How to measure phase difference of 2 signals using IQ demodulator

Can you offer guidance or do you also need help?

**Physics Forums | Science Articles, Homework Help, Discussion**