氢原子钟辅助电子学系统电路设计改进

A Design of Improved Circuits of the Auxiliary Electronic System of a Hydrogen Maser

氢原子钟辅助电子学系统已稳定工作多年,但是与目前的先进技术相比,原来的设计理念已显陈旧,同时暴露出外围电路庞杂、故障点比较多、问题查找困难等诸多问题;运用ARM+FPGA模式对电路进行了改进,其中运用12 bit高精度模数转换芯片实现参数采样,数字化设计改进氢原子钟智能温度控制系统,采用直接数字式频率合成器(Direct Digital Synthesizer,DDS)技术设计产生综合器频率信号,简化设计实现氢原子钟的通信功能;从测试结果来看,提高了参数的采样精度,数字化的智能温控模式实现了温度的自动化智能调整,直接式频率合成器技术简化了设计电路,基于i Coupler磁隔离技术的隔离型RS-232接口收发器设计提高了接口的稳定性;从整体设计来看,大大简化了设计电路,提高了系统性能及可靠性。

The auxiliary electronic system of the first hydrogen maser in China has been working for many years. Nevertheless, the design of this system is outdated and the system has certain defects such as complicated peripheral circuits, many fault points, and occurrences of malfunctions not easily discernable. In this paper, we present a design of improved circuits of the auxiliary electronic system using the ARM＋FPGA scheme. The design adopts 12-bit high-precision analog-to-digital conversion chips for wideband sampling, and incorporates a digital mode to improve the intelligent temperature control of the system. In the design we also use the DDS technology to generate signals for the frequency synthesizer. The design is simplified enough to realize communication of the system with the hydrogen maser. We have carried out tests of the design. The tests show that the design improves precisions of signal sampling, effective intelligent temperature adjustment has been realized with the digital temperature-control mode, circuit simplification has been achieved through the DDS technology, and the stability of the interface has been enhanced by the isolated RS-232 transceiver based on the iCoupler magnetic isolation technology. Overall, our design dramatically improves the capability and reliability of the system yet in the mean time simplifies the system.