Frequency synthesizer for cesium atomic clock

Abstract

Disclosed is a frequency synthesizer for a cesium atomic clock, the frequency synthesizer is designed by utilizing the characteristic of nonlinear output of an AD9852 chip, a circuit structure of an AD9852 + filter is adopted, 80 MHz serves as a reference signal, a signal with the frequency of 87.3 MHz is output, the circuit structure is simple, the size is small and no local oscillator signal needs to be additionally used. While the quality of output signals is guaranteed, miniaturization of a frequency source of the frequency standard circuit is achieved, control parameters are convenient to calculate, and the frequency standard circuit can be installed in a 3U case.

Description

technical field [0001] The invention belongs to the technical field of atomic clocks, in particular to a frequency synthesizer for cesium atomic clocks. Background technique [0002] The cesium atoms in the ground state (F=3, mF=0) are excited by the microwave signal to obtain energy, and then transition to the excited state (F=4, mF=0). The cesium atomic clock uses the frequency v of the excitation signal and the center frequency v of the spectral line _0 The difference value acts as a frequency discriminator, so that the cesium atomic clock can output a stable and accurate frequency signal. [0003] In the currently commonly used cesium atomic clock frequency synthesis scheme, in addition to the 10MHz local oscillator signal, it is usually necessary to use an additional 100MHz local oscillator signal for phase discrimination with the 7.3MHz signal generated by the AD9852. Due to the use of two crystal oscillators in this solution, the circuit structure is relatively comp...

AI Technical Summary

Problems solved by technology

Due to the use of two crystal oscillators in this scheme, its circuit structure is relatively complex and the volume is large, and it is impossible to realize the miniaturization of the frequency standard circuit of the cesium atomic clock

According to the Nyquist sampling theorem, it is impossible to use 80MHz as a reference signal, and the DDS signal generator directly outputs a signal of 87.3MHz

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