Timing Misalignment
Signal distortion occurs when the reference signal used for extraction does not perfectly align with the incoming sensor wave. In high-frequency detection chains, synchronous demodulation phase error causes a portion of the quadrature signal to leak into the main channel, creating a bias that shifts with input intensity. This error is common in sensors using carrier-based amplification where latency in the feedback path is not perfectly compensated.
Harmonic Impact
Filtering strategies struggle to isolate the true signal from the interference when the phase shift is subtle but consistent. Because demodulation relies on multiplying the signal by a timed square or sine wave, synchronous demodulation phase error reduces the overall gain of the output while increasing noise sensitivity. Every degree of mismatch translates into a direct loss of resolution.
Designers use delay lines or digital clock adjustment to tighten the lock between phases.
Measurement Variance
Deviations between the drive clock and the detection logic often fluctuate with temperature. Testing cycles verify that the synchronous demodulation phase error remains within a narrow corridor across all operating modes. If the error drifts, it forces the zero-offset value of the sensor to crawl upward or downward.
Stability is confirmed by checking the rejection of signals placed ninety degrees out of phase from the target carrier.
Limit Of Control
Real-time correction engines monitor the phase gap using reference pilots. Accuracy reaches its boundary when the sampling clock jitter exceeds the phase adjustment resolution. In large production runs, synchronous demodulation phase error is quantified through automated diagnostic software that sweeps the timing parameters.
If the system cannot hold a stable phase lock, the frequency range of the device is typically restricted.
