Method and circuit of digital measurement of the phase of a sinusoidal signal

摘要

A method for measuring with a maximum error E the phase of a substantially sinusoidal signal, of angular frequency omega=2pi/T, sampled with a sampling period T/r, in which the phase is calculated as the time at which a straight line crossing two consecutive samples located on either side of a median value of the signal reaches said value, including the step of selecting number r from a range included between a value r 0 and a value equal to from two to three times value r 0 , such that: $E>={\max }_{t\in \left[\frac{-T}{\mathrm{r0}},0\right]}\left[t-\frac{T}{\mathrm{r0}}.\frac{\mathrm{round}\left(G.\sin \mathrm{omega}t\right)}{\mathrm{round}\left(\sin \left[G.\mathrm{omega}.t+\frac{2\mathrm{pi}}{\mathrm{r0}}\right]\right)-\mathrm{round}\left(G.\sin \mathrm{omega}t\right)}\right]$ round(x) being the integer closest to a real number x and G being equal to 2ⁱG₁, where i is the number of bits on which are coded the samples and where G₁ is a term of correction of the amplitude of the sampled signal.