Digital precision phase-shift method and phase shifter

Abstract

This invention discloses a method for precisely shifting phases and a phase-shifter, first of all, which cuts a HF input signal in a counter, which outputs a low frequency square wave signal to be shifted, secondly outputs a two double frequency square wave signal of the being shifted signal, thirdly switches the HF input signal and the two double frequency square wave signal in a preset counter to output a phase-shift square wave labeling square wave and fourthly switches the shift labeling square wave and the low frequency signal to be shifted in a trigger to output the shifted low frequency square wave to finish the phase shift. Device realizing said method include a counter and preset counter and a trigger.

Description

technical field [0001] The invention relates to a digital precision phase shifting method for an atomic clock, and also relates to a phase shifter, which can be widely used in various atomic clocks and precision time equipment. Background technique [0002] In atomic clocks and precision time equipment circuits, there are various methods to achieve phase shifting, but they can be roughly divided into three categories. One is analog phase shifting, which uses amplifiers plus RC phase shifting networks or shift filters. The mechanism is to use the phase-frequency characteristics of the filter network to achieve the purpose of phase shifting, but due to the discrete linear components (such as capacitors, resistors, etc.) It is directly related to power supply fluctuations, so the phase shifting phase value has large fluctuations and it is difficult to make the phase shifting accuracy high; the other is to use the transmission delay time (propagation delay) of the digital gate c...

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Problems solved by technology

[0002] In atomic clocks and precision time equipment circuits, there are various methods to achieve phase shifting, but they can be roughly divided into three categories. One is analog phase shifting, which uses amplifiers plus RC phase shifting networks or shift filters. The mechanism is to use the phase-frequency characteristics of the filter network to achieve the purpose of phase shifting, but due to the discrete linear components (such as capacitors, resistors, etc.) It is directly related to power supply fluctuations, so the phase shifting phase value has large fluctuations and it is difficult to make the phase shifting accuracy high; the other is to use the transmission delay time (propagation delay) of the digital gate circuit for phase shifting. This method only It is used when the phase shift frequency is high and the phase shift value is relatively fixed. If you want to modify the phase shift value, you must modify the number of stages of the gate circuit. Obviously, the modification flexibility of this method is poor; the third method is to use The program statement of the single-chip microcomputer is used for software delay or programmable device (such as CPLD, FPGA, etc.) for controllable hardware delay. This method has a wide range of phase shift, high precision, easy modification, and stable phase shift. It is currently applied It is wide, but in some special occasions, it is forbidden to use devices such as single-chip microcomputers, programmable devices, and memories, and the methods suitable for these devices are difficult to implement with discrete circuits, so the use of such methods in some special occasions is limited.

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