Dephaser circuit

Claim 2

A phase-shifting circuit adapted to receive a first periodic signal of frequency f o comprising: a digital counter having N stages for cyclically counting the number of periods of the signal of frequency f o and delivering in response thereto a second periodic signal of frequency f o /2 N represented by a binary number M; a number generator for providing a selectable binary number K; digital adder means connected to said counter and said number generator for receiving said number M and said number K and instantaneously delivering a binary number M+K equal at all times to the true sum of said number M and said number K, said number M+K corresponding to a third periodic signal equal in frequency to said second periodic signal and having a phase shift therebetween of an amount determined by said number K.

Claim 3

A phase-shifting circuit according to claim 1, wherein said number generator comprises means providing a number K of constant value, said means being capable of modifying said value in an arbitrary manner.

Claim 4

A phase-shifting circuit according to claim 2, wherein said means comprises a digital switch for producing and entering a number, a memory connected to said switch to record said number in response to a control signal, and a control means for delivering said control signal to said memory, the output of said memory being connected to the output of said number generator.

Claim 5

A phase-shifting circuit according to claim 1, wherein said number generator comprises means for modifying the number K in a predetermined manner.

Claim 6

A phase-shifting circuit according to claim 4, wherein said number generator has an input adapted to receive a fourth periodic signal, and wherein said modifying means comprises a digital switch for producing and entering a second number; a sign selector for producing and entering the sign of said second number; a preset counter for counting said fourth periodic signal and adapted to be preset by said second number, said preset counter having a preset input connected to said digital switch and having a clock input connected to said input of said number generator; and a first reversible counter having a clock input connected to the output of said preset counter for counting the output pulses of said preset counter, and having a counting direction determination input connected to said sign selector for controlling the direction of counting, the output of said reversible counter being connected to the output of the number generator.

Claim 7

A phase-shifting circuit according to claim 1, wherein said number generator comprises first means having a first digital switch for producing and entering a first number, a memory connected to said first switch to record said first number in response to a control signal, and a control means for delivering said control signal to said memory; wherein said number generator has an input adapted to receive a fourth periodic signal and further comprises second means having a second digital switch for producing and entering a second number, a sign selector for producing and entering the sign of said second number, a preset counter for counting said fourth periodic signal and adapted to be preset by said second number, said preset counter having a preset input connected to said second digital switch and having a clock input connected to said input of said number generator, and a first reversible counter having a clock input connected to the output of said preset counter for counting the output pulses of said preset counter, and having a counting direction determination input connected to said sign selector, for controlling the direction of counting; and wherein said number generator further comprises second digital adder means for adding the output signals of said memory and said reversible counter, the outputs of said memory and said reversible counter being respectively connected to a first and a second input of said second adder means, the output of said second adder means being connected to the output of the number generator.

Claim 8

A phase-shifter in accordance with claim 1, comprising a first phase control circuit having a frequency mixing input connected to the input of the phase-shifting circuit and having a phase comparison input connected to the output of said digital counter so that the frequency and the phase of the output signal of the first phase control circuit are maintained equal to the differences between the frequencies and, respectively, the phases of the first and of the second periodic signal; and a second phase control circuit having a frequency mixing input connected to the output of said first phase control circuit and having a phase comparison input connected to the output of said digital adder means so that the frequency of the output signal of said second phase control circuit is equal to the frequency of the first periodic signal and its phase differs from that of the first periodic signal by a quantity determined by the number K.

Claim 9

A phase-shifter in accordance with claim 7, in which said output of the second phase control circuit is connected to a first input of a phase comparator, said phase comparator having a second input adapted to receive a fifth periodic signal; and wherein said number generator comprises a reversible counter, having an output connected to the output of the number generator, and having incrementation and decrementation inputs respectively connected each through a threshold detector to an output of an integrator, said integrator having an integration input connected to an output of said phase comparator and having a reset input connected through a logic circuit to outputs of said threshold detectors, so that the output of the number generator presents a number determined by the phase difference existing between said first and said fifth periodic signals.