CN-121995722-A - Cold atom microwave Zhong Weibo generation device and method

CN121995722ACN 121995722 ACN121995722 ACN 121995722ACN-121995722-A

Abstract

The invention provides a cold atom microwave Zhong Weibo generating device and a method, wherein the cold atom microwave Zhong Weibo generating device comprises a high-stability voltage source, a reference clock signal generating module, a control module and a digital-to-analog converter, wherein the high-stability voltage source is electrically connected with the digital-to-analog converter and is used as a reference voltage source of the digital-to-analog converter and is used for generating a reference voltage of the digital-to-analog converter, the reference clock signal generating module is electrically connected with the digital-to-analog converter and is used for generating a reference clock signal of the digital-to-analog converter, the control module is electrically connected with the digital-to-analog converter and is used for controlling the output frequency or the output amplitude of the digital-to-analog converter, and the digital-to-analog converter generates a synthesized signal, namely a target microwave frequency signal, by utilizing the mixing characteristic under the control of the control module based on the reference clock signal. The cold atom microwave Zhong Weibo generating device adopts a digital circuit processing method to directly generate a target microwave frequency signal, so that the immunity characteristic and the anti-interference capability of a microwave source to the ambient temperature can be improved, and in addition, the microwave circuit of the cold atom microwave Zhong Weibo generating device is simple in structure and low in cost.

Inventors

REN SHIQING
WANG XIUMEI
LI YUEBAO
LIU GUODONG
WANG DANYANG
WANG YIFEI

Assignees

北京无线电计量测试研究所

Dates

Publication Date: 20260508
Application Date: 20251226

Claims (10)

1. A cold atom microwave Zhong Weibo generating apparatus, comprising: A high-stability voltage source (1) electrically connected with the digital-to-analog converter (4) and used as a reference voltage source of the digital-to-analog converter (4) for generating a reference voltage of the digital-to-analog converter (4); a reference clock signal generating module (2) electrically connected with the digital-to-analog converter (4) and used for generating a reference clock signal of the digital-to-analog converter (4); The control module (3) is electrically connected with the digital-to-analog converter (4) and is used for controlling the output frequency or the output amplitude of the digital-to-analog converter (4); the digital-to-analog converter (4) generates a composite signal, namely a target microwave frequency signal, by utilizing a mixing characteristic under the control of the control module based on the reference clock signal.
2. A cold atom microwave Zhong Weibo generating device as claimed in claim 1, characterized in that the reference clock signal generating module (2) comprises: a signal source (21) for generating a clock signal; -a dielectric resonator oscillator (22) electrically connected to said signal source (21) for outputting a frequency signal, said frequency signal being locked on said clock signal, said frequency signal being used as said reference clock signal for said digital-to-analog converter (4).
3. A cold atom microwave Zhong Weibo generating device as claimed in claim 1, characterized in that the control module (3) comprises: A control unit (31) for generating control words; And one end of the read-only memory (32) is electrically connected with the control unit (31), the other end of the read-only memory is electrically connected with the digital-to-analog converter (4), memory parameters of the read-only memory are set based on the control word, and a control data stream is output, and is used for controlling the output frequency or the output amplitude of the digital-to-analog converter (4).
4. A cold atom microwave Zhong Weibo generating device according to claim 3, characterised in that the control unit (31) is also electrically connected to the dielectric resonator oscillator (22) for controlling the dielectric resonator oscillator (22) to output the frequency signal.
5. The cold atom microwave Zhong Weibo generating device according to claim 3, wherein the control module (3) further comprises a communication port (33) electrically connected with the control unit (31) and used for communicating with an upper computer to realize transmission of control instructions.
6. A cold atom microwave Zhong Weibo generating device according to claim 1, characterised in that the high-stability voltage source (1) is a dc power supply.
7. A cold atom microwave Zhong Weibo generating device as claimed in claim 2 wherein the frequency signal is a high frequency signal.
8. A cold atom microwave Zhong Weibo generating device as claimed in claim 1, characterized in that the digital-to-analogue converter (4) has a number of operation bits of 16 bits.
9. A cold atom microwave Zhong Weibo generating device according to claim 1, characterized in that the frequency of the reference clock signal is 2500MHz, the control module (3) controls the output frequency of the digital-to-analog converter (4) to 665.31739MHz, and the frequency of the target microwave frequency signal is 6834.682610MHz.
10. A method for generating cold atom microwaves Zhong Weibo, comprising the steps of: generating a reference voltage of a digital-to-analog converter; generating a reference clock signal for the digital-to-analog converter; controlling the output frequency or the output amplitude of the digital-to-analog converter; the digital-to-analog converter generates a composite signal, i.e., a target microwave frequency signal, based on the reference clock signal using a mixing characteristic.

Description

Cold atom microwave Zhong Weibo generation device and method Technical Field The invention relates to the field of cold atomic frequency standards, in particular to a cold atomic microwave Zhong Weibo generating device and method. Background The cold atom microwave clock mainly utilizes the interaction of a separation oscillation field between cold atoms and microwaves to generate a frequency discrimination curve, so that a local oscillator outputs a frequency signal with high stability and high accuracy. The microwave cavity is used as a core device of the cold atomic clock, and a place for transition between a microwave radiation field and two hyperfine energy levels of a cold atomic ground state is provided after atoms are cooled, but a specific microwave signal is required to be injected into the microwave cavity externally so as to form a required microwave energy field in the microwave cavity. For example, in a fountain clock based on rubidium atoms, microwave signals with pi pulses on time sequence are required to be injected into a selected-state microwave cavity to perform state preparation on the rubidium atoms, partial atoms with energy levels on a ground state are prepared to the energy levels on the ground state, meanwhile, microwave signals with pi/2 pulses on time sequence are required to be respectively injected into an excitation microwave cavity twice to perform separation oscillation field interaction with the rubidium atoms, so that a Ramsey frequency discrimination curve is formed, and in an integrating sphere cold atomic clock based on the rubidium atoms, only microwave signals with pi/2 pulses on time sequence are required to be respectively injected into a unique microwave cavity twice to perform separation oscillation field interaction with the rubidium atoms, so that the Ramsey frequency discrimination curve is formed. From the above two examples, it can be seen that in the cold atomic clock, the microwave signals directly interact with rubidium atoms, and the output frequency and the power stability of the microwave signals directly determine the atom state selection efficiency, the signal-to-noise ratio of the Ramsey frequency discrimination curve and the stability of the output signals after final closed-loop locking of the whole clock. The microwave signal is generated by a specific microwave source, the microwave source is built by a plurality of microwave devices and the like, and the working characteristics of the microwave devices are all related to the ambient temperature, namely, the characteristics of the WeChat signal are influenced by the ambient temperature. In summary, the sensitivity of the microwave signal to the ambient temperature is converted into the sensitivity of the stability of the output signal to the ambient temperature after the atomic state selection efficiency, the signal to noise ratio of the Ramsey frequency discrimination curve and the final whole clock closed loop locking. Therefore, it is needed to reduce the sensitivity of the microwave signal to the ambient temperature, so as to reduce the sensitivity of the stability of the output signal to the ambient temperature after the final whole clock is closed-loop locked, namely, to improve the anti-interference and immunity of the whole clock to the ambient temperature, further improve the stability and robustness of the working performance of the whole clock, and finally improve the long-term holding capacity of the cold atomic clock performance, thereby laying a foundation for the engineering development of the cold atomic clock and popularization and application in harsh scenes such as non-laboratory environments. In the prior art, aiming at a cold atomic microwave clock based on rubidium atoms, a DDS is mainly adopted to generate a microwave signal with the decimal frequency of 34.682610MHz, and then the microwave signal is mixed with a DRO (DIELECTRIC RESONATOR OSCILLATOR ) with the frequency of 6800MHz to output a 6834.682610MHz microwave signal finally required. The temperature characteristic of 6834.682610MHz microwave signal amplitude is directly determined by the temperature characteristic of DDS, mixer, DRO and other devices, but the temperature characteristic of these devices is generally 1000-2000 ppm/DEG C, which results in that the temperature characteristic of 6834.682610MHz microwave signal stays at 1000 ppm/DEG C level, and the requirement of the cold atomic microwave clock for future long-term stability cannot be met. If the temperature characteristic is to be improved, more subsequent auxiliary circuit processing such as a stable amplitude loop, a temperature control circuit and the like are required, so that the complexity of the circuit is increased, the cost of a microwave source is increased, and the reliability and the robustness of the whole clock are reduced. Therefore, there is a need for a cold atom microwave Zhong Weibo generating device that can improve the immunity of t