Looped network dual-channel time frequency high-precision transmission device

Abstract

The invention provides a looped network dual-channel time frequency high-precision transmission device, which comprises an optical fiber first interface and an optical fiber second interface, and a second pulse signal and a frequency signal are transmitted between the optical fiber first interface and the optical fiber second interface through an optical fiber. The device has the advantage of strong anti-interference capability. And the frequency signal output by the crystal oscillator is adjusted in a manner of combining digital control and analog quantity control to obtain high-precision time frequency transmission with high transmission precision, low noise and high frequency stability.

Description

Technical field[0001]The present invention relates to a ring network dual channel transfer device, in particular a ring network dual channel time frequency high-precision transmission device, which belongs to the field of time frequency.Background technique[0002]The current high-precision time frequency output device is the atomic, molecular energy level difference as a reference signal to calibrate the crystal oscillator to output a standard frequency signal. It utilizes the signal generated by the atomic energy level, and obtains a negative feedback correction signal used to correct the crystal oscillation after the signal processing, so that it outputs a steady oscillation frequency to accurately calculate the time.[0003]Since the frequency stability and accuracy of different atom clocks have a minute deviation, this deviation affects the accuracy of the time frequency output, resulting in the time of the time frequency output device output from the respective places that cannot ...

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Problems solved by technology

[0003]Because the frequency stability and accuracy of different atomic clocks have slight deviations, such deviations affect the accuracy of time and frequency output, resulting in the output of time and frequency output devices in various places The time cannot be completely synchronized, and the time output between each other has a certain difference

[0004] At present, there are proposals for time-frequency local area network propagation, but most of them are one-way propagation or partial one-way propagation, such as two-way propagation of pulse signals and one-way propagation of frequency signals. Since the precise position of the rising or falling edge of the second pulse signal is difficult to accurately locate, the accuracy of time transfer is prone to problems

[0005]Usually in the high-precision transmission of time and frequency, the transmission of the second pulse signal and the transmission of the frequency signal are carried out separately. Although two channels are occupied, the frequency signal is often only It is used to eliminate the line delay, and only uses the second pulse signal as the mark of the time signal, so the accuracy of time transmission is difficult to improve

[0006] In the prior art, there is still a method of using a single channel to transmit the second pulse signal and the frequency signal. Although the time accuracy of the single channel transmission is relatively high, in practical applications , the time accuracy of single-channel transmission is often higher than the usage requirements

In addition, the single-channel transmission method has poor short-term stability of the transmitted frequency signal, which makes it have higher requirements on the crystal oscillator, resulting in high system cost

[0007]In addition, in the transmission of time with high precision, the frequency signal is an analog quantity. When transmitting the time signal, it is necessary to consider the line delay. Usually, the A / D module is used to convert the frequency The signal is converted into a digital quantity, and then the transmission frequency phase is controlled to eliminate the line delay, but the adjustment speed is slow and the frequency stability is insufficient, which restricts the further improvement of the time transmission accuracy

[0008] An intermediate node device is also disclosed in the prior art. By setting an intermediate node device between the dual-channel time-frequency transmission devices, the time-frequency can be obtained at the intermediate node , to achieve the effect of transmitting time and frequency to multiple places, but the traditional dual-channel time-frequency transmission device requires two sets of equipment at the remote end and the local end, which not only has high cost, but also high equipment complexity

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