直接数字频率合成技术在四极质谱仪射频电源中的应用

四极质谱仪射频电源的驱动电路大多采用模拟电路搭建而成, 频率相对固定。然而, 由于射频电源在驱动不同负载时所需的频率各不相同, 因此, 若要驱动不同负载, 必须改变模拟器件的硬件参数, 过程比较繁琐。针对此不足, 研发了一种新型的射频电源的频率发生电路。该电路结合了直接数字频率合成(DDS)技术和高级精简指令集(ARM)型微控制器, 通过上位机配置, 可输出频率和相位可调的正弦波信号, 频率可调范围为0~15 MHz, 分辨率是0.023 28 Hz。实验表明, 该频率发生电路结构简洁, 性能稳定、可靠, 已成功用于四极质谱仪射频电源中。

Application of direct digital frequency synthesis technology in radio-frequency power of quadrupole mass spectrometer

The radio-frequency power drive circuits of the quadrupole mass spectrometer are mostly built in the analog design with relatively fixed frequencies. However, because the radio-frequency power required different frequencies when driving different loads, it’s necessary to change the hardware parameters of the analog components, which is a cumbersome process. To overcome this defect, a novel frequency-generating circuit for the radio-frequency power was developed. The design combined the direct digital frequency synthesis (DDS) technology and the advanced RISC machine (ARM) microcontroller, and after being configured on the host computer, could output frequency- and phase-adjustable sine wave signals, whose frequency was adjustable from 0 to 15 MHz and whose resolution was 0.023 28 Hz. Experiments showed that the frequency-generating circuits had simple structures and stable and reliable performance.It has been successfully used in the radio-frequency power of the quadrupole mass spectrometer.