Phased based sensing

摘要

Interrogation of a phase based transducer is performed by temporally overlapping and interfering a single pulse output from the transducer to determine the rate of change with time of the measurand represented as a phase change. The rate of change, or derivative of the phase change typically has a much smaller amplitude than the signal itself, and the derivative measurement therefore has reduced sensitivity. In this way, large amplitude signals which might otherwise be subject to overscaling effects can be measured more effectively.

主权项

1. A method of interrogating a phase based transducer, said transducer providing a change in phase of signal propagation in response to a sensed parameter, said method comprising:
passing a single pulse through the transducer, and receiving the single pulse at a phase detector, combining a delayed version and an undelayed version of said single pulse signal within the phase detector, the delayed and undelayed versions both having passed through the transducer; and determining from said combination a measure of the rate of change of phase with time of said signal.