Gatedrift

Gatedrift is a term used in electronics and measurement science to describe time-dependent drift in a signal that is introduced or amplified by a gating process. It occurs in systems that sample or route signals through switches or gates, where the act of opening and closing a signal path creates a changing baseline or offset over time. Gatedrift can arise in various contexts, including switched-capacitor circuits, time-of-flight detectors, and ion gates used in spectrometers or other gating-based measurement setups.

The mechanisms behind gatedrift are related to how a gate or switch interacts with the signal path. Charge injection from the switching element, clock feedthrough, and variations in the parasitic capacitances can impart transient or slowly varying perturbations to the stored charge or voltage. Leakage currents, changes in gate-to-channel coupling, and temperature or supply voltage fluctuations can modulate these effects, causing baseline wander, offset drift, or slow gain changes between gating events.

In practice, gatedrift affects measurement accuracy, dynamic range, and timing resolution. It can complicate calibration, produce biases in processed data, and mimic slow signals if not properly accounted for. The severity of the effect depends on the gate design, switching frequency, duty cycle, and the surrounding circuitry.

Mitigation strategies include selecting low-injection switches, employing bootstrapped or differential gating, and using sampling schemes that minimize charge perturbations. Techniques such as correlated double sampling, guard signaling, careful clocking, and rigorous temperature and supply regulation are commonly used. Calibration and post-processing can further reduce the impact of gatedrift on final measurements.

See also: drift in electronics, gate, charge injection, switched-capacitor circuit, time-of-flight detectors, ion gate.