Process and device for sampling a sine wave signal by a multiple frequency signal

A device for sampling a sine wave input signal E(t), having a frequency F and cycle T and a phase, by a sampling signal A(t) of multiple frequency kF where k is a positive integer and producing a minimum relative phase displacement between said signals, comprising:

• controlled oscillator means, having an output, for generating a reference signal D(t) having a frequency kF and a phase which is dependent on said input signal phase;
• phase regulating means, having an inpuut connected to said output of said controlled oscillator means and a displacement control input and an output supplying said sampling signal A(t), for receiving said reference signal D(t) and generating said sampling signal A(t) having a plurality p of possible phase settings each one being shifted by T/kp with respect to its neighboring phase shift setting;
• analog-digital converter means, having a sampling input, for converting said input signal E(t) into a digital output signal S(t) and receiving at said sampling input said sampling signal A(t);
• displacement control means, having first and second inputs, said first input being connected to said output of said phase regulating means and said second input receiving said digital output signal S(t), and one output connected to said displacement control input of said phase regulating means, for measuring the relative phase displacement between said input signal E(t) and said sampling signal A(t), and for selecting one of said plurality of phase settings which minimizes said relative phase displacement.

Apparatus for sampling a sine wave input signal E(t) having a phase and a frequency F and a cycle T, with a sampling signal A(t) having a frequency kF, k being a positive integer, to produce a sampled digital signal S(t) having a minimum relative phase difference from said signal E(t), comprising:

• means, adapted to receive said signal E(t), for generating a plurality p of signals Ai(t) each having a frequency kF and a phase which is adjusted by T/kp with respect to neighboring ones of said plurality of signals Ai(t), p being a positive integer;
• means connected to said generating means, for providing said sampling signal A(t) which is one of said plurality of signals Ai(t) having a minimum phase difference from said signal E(t) phase;
• and
• means, connected to said providing means and adapted to receive said signal E(t), for converting said signals E(t) and A(t) into said sampled digital signal S(t).

A method of sampling a sine wave input signal E(t) having a phase and a frequency F and a cycle T, with a sampling signal A(t) having a frequency kF, k being a positive integer, to produce a sampled digital signal S(t) having a minimum relative phase difference from said signal E(t), comprising the steps:

• receiving said signal E(t) and generating a plurality p of signals Ai(t) each having a frequency kF and a phase which is adjusted by T/kp with respect to neighboring ones of said plurality of signals Ai(t), p being a positive integer;
• providing said sampling signal A(t) which is one of said plurality of signals Ai(t) having a minimum phase difference from said signal E(t) phase;
• and
• converting said signals E(t) and A(t) into said sampled digital signal S(t).