基于LabVIEW的同轴开关切换系统设计及应用

Design and Application of Coaxial Switching System Based on LabVIEW

摘要:

精密自动化测量和射频应用领域,自动开关切换系统具有广泛应用,设计高效率、抗干扰的开关自动切换系统在相关领域具有重要应用价值;普通电磁继电器易受外界电磁干扰和射频干扰影响,同时被控线路中会被引入电磁噪声,在精密测量和射频应用领域产生误差,所以选择屏蔽良好的同轴开关是最佳解决方案;控制端采用可视化编程语言G语言设计控制界面,基于LabVIEW平台,通过DAQmx硬件驱动,实现同轴继电器开关的程序控制切换和同轴线路的自动开启或关闭功能;此同轴开关切换系统应用于精密可编程电容器,同轴开关控制23个近似满足二进制关系的电容,用精密电容电桥检测电容输出值;实验数据表明,此同轴开关切换系统准确实现任意电容的切换,并减少了外界干扰,提高了系统的测量精度和自动化程度。

Abstract:

In the precision automatic measurement field and the radio frequency field, the switch system has a wide range of applications. So a high efficiency, anti-interference switch system has important practical value. Ordinary electromagnetic relays are easily influenced by EMI/RFI, at the same time they bring electromagnetic noise to the lines. In the field of precision measurement and RF applications, such relays cause error. So the coaxial switch with good shielding was the best solution. Using G programming language designed the user interface. Based on the LabVIEW platform, through DAQmx hardware driver, coaxial relays were controlled by program to switch and coaxial circuit could automatically turn on or turn off. In the application of coaxial switch system in the programmable capacitor, coaxial switch controlled 23 binary-weighted capacitor elements. Capacitance bridge was used for testing the output value. The result reflected that this coaxial switch based on LabVIEW can switch any capacitor. The interference were reduced, at the same time, the precision and automation of the system were greatly improved.