What Does Timing Skew Mean in RFmx Waveform Creator ?

Updated Feb 5, 2025

Issue Details

I see parameter Timing Skew in RFmx Waveform Creator when I want to generate IQ data for WLAN, but I don't know what it means.Screenshot 2025-02-04 125447.png

Solution

Refer to IQ Impairments, we can see 

  • IQ gain imbalance (dB) is the amount of amplifier and filter gain imbalance between I and Q signals. Quadrature skew (deg) is the deviation in angle from 90 degrees between the I and Q signals.
  • Timing skew (s) is the difference in sampling instances of I and Q signals.
  • Both timing skew and quadrature skew contribute to the phase mismatch between I and Q signals.
The above three quantities follow the below definition.

where G = 10(IQ Gain Imbalance/20),

φ is the quadrature skew, τ is the timing skew,

I'(t) is the impaired in-phase component of the signal,

Q'(t) is the impaired quadrature-phase component of the signal,

I(t) is the ideal in-phase component of the signal,

and Q(t) is the ideal quadrature-phase component of the signal.