Directive transducer system for Doppler measurements - includes phase shift correction and comparator circuits to ensure received signals arrive from predetermined direction

摘要

The appts. uses transducers which are connected to a phase shift circuit which compensates for the transducer output signals to ensure that the signals are in phase when received from a partic. direction. A phase comparator contains limiters which square the phase shift circuit outputs. These signals are applied to a test circuit containing gates to produce a gating signal for a gate receiving the output from a check circuit. The check circuit contains delays in two reference circuits to enable a tolerance signal to be generated for the identification of the phase of the input signals. The output passes through the gate to a modulator operating the phase shifted sum of the output signals from the input phase shift circuit. A measuring circuit determines the information content of the modulated signals.