| 摘要 |
<p>Apparatus for tracking the peak of a correlation function between two signals (x(t),y(t)) includes a coarse peak detector (26) for providing a coarse measure of the peak position and a tracking correlator for providing a fine indication of the peak once its tracking range has been set by the coarse detector. The preferred tracking correlator includes a word controlled shift register (25) whose length is controlled by a signal (Np) from the coarse detector (26) thereby setting the tracking range. A delay-lock-loop including a multiplier (16), smoothing circuit (18), integrator (19) and voltage controlled oscillator (20) achieves a stable state when the clock frequency (Fc) of the register (25) produces a null at the input to the integrator (19). A preferred use of the apparatus is as a flowmeter. </p> |
