A high-bandwidth radio frequency signal arrival time measurement device and method

Abstract

The invention provides a device for measuring the time of arrival of a high-bandwidth radio frequency signal. The device comprises the following parts: an electrooptical modulator connected with a radio frequency signal to be measured; a reference signal source comprising a femtosecond laser device and a low-noise radio frequency signal source, wherein the femtosecond laser device is connected with the electrooptical modulator, and is located in a phase-locked loop, and the low-noise radio frequency signal source is connected to the input end of the phase-locked loop; and a photoelectric detector connected with the electrooptical modulator. According to the device for measuring the time of arrival of the high-bandwidth radio frequency signal, which is disclosed by the invention, the extremely low-noise femtosecond laser device is locked onto the low-noise radio frequency source through a phase-locked loop technology; the reference signal source with excellent noise performance is modulated through the electrooptical modulator according to the radio frequency signal to be measured; time of arrival information can be demodulated only by measuring an amplitude value of the modulated signal, so that high-precision time measurement resolution is realized; and furthermore, a laser pulse string is little interfered and affected by the outside in a transmission process, so that introduced external noise is lower.

Description

technical field [0001] The invention relates to a time measurement method, in particular to a method for measuring the arrival time of a high-bandwidth radio frequency signal. Background technique [0002] With the development of science and technology, especially in the field of accelerators (synchrotron radiation sources, free electron lasers, linear colliders, etc.), phased array radars and radio telescope clusters, etc., the requirements for the resolution of signal arrival time measurement are increasing. [0003] There are two main methods for measuring the time of arrival of signals at present. [0004] one such as figure 1 As shown, the RF signal to be tested is mixed with another known same-frequency low-noise RF reference signal source 1' through a mixer 2', and the sum frequency signal is filtered out through a low-pass filter 3', leaving only the difference The frequency signal, that is, the baseband signal, the arrival time signal of the RF signal to be tested...

AI Technical Summary

Problems solved by technology

[0021] Since low-noise RF signal sources perform better at low frequencies and poorer at high frequencies, the performance limitations of low-noise RF signal sources will affect the final resolution of the time-of-arrival measurement of the measured signal; on the other hand, analog-to-digital conversion The clock jitter performance of the input clock to the device will also affect the resolution of the time-of-arrival measurement of the signal under test

[0022] In summary, the shortcoming of the prior art is that it is necessary to provide a radio frequency reference signal source with low noise performance, the noise performance of the reference signal source will limit the measurement resolution of the time of arrival of the radio frequency signal to be tested, and the existing reference signal source in the low frequency band ( 1Hz to 1KHz) has good noise performance, and the high frequency band (1KHz to 10MHz) has poor performance

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