DEVELOPMENT OF AN AMPLITUDE AND FREQUENCY STABILIZED HIGH POWER OSCILLATOR

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 在质谱学中，多极离子导常由高压振荡器驱动。这种“电源”通常提供数百千赫至几兆赫频率范围内的正弦波，其幅度不到几千伏，以有效地将离子通过多极传输。当直流电势差作用于具有相反极性的射频信号的棒时，四极离子导可用作质量过滤器。驱动四极子质量滤光器需要高稳定性振荡器。这项工作(Lin等人，2009)提出了一种简单、低成本的设计，以保持高功率振荡器的输出频率和幅度。 一种简单、低成本的设计正在测试中，它包括一个提供稳定参考频率的“种子”晶体和一个稳定输出幅度的AGC电路。目标是频率稳定度在30ppm以内，幅度稳定度在0.1%以内。为了实现这一目标，设计的电路分为两部分：信号基准源和放大级。测试了几种不同类型的晶体振荡器，研究了将参考信号匹配到放大级的阻抗问题。正在进行放大晶体管的电路测试，以检测合适的晶体管作为功率放大器，进一步放大参考信号。此外，高功率双极结晶体管的使用和变压器的改进应该提供更高的驱动电压，这对于质量过滤应用是有用的，特别是对MALDI产生的高m/z离子。 研究了在保持性能的前提下，最终输出信号与四极子匹配的优化方案。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. In mass spectrometry, multipole ion guides are commonly driven by high voltage oscillators. Such "power supplies" usually provide sine waves in the frequency range of hundreds of KHz to a few MHz with the amplitude of less than several KV to efficiently transport ions through the multipoles. A quadrupole ion guide can be operated as a mass filter when a DC potential difference is applied to the rods of opposite polarity RF signal. High stability oscillators are required to drive quadrupole mass filters. This work (Lin et al., 2009) presents a simple, low-cost design for maintaining the output frequency and amplitude of a high power oscillator. A simple, low-cost design that incorporates a "seed" crystal to provide a stable reference frequency and an AGC circuit to stabilize the output amplitude is being tested. The goal is to achieve the frequency stability within 30 ppm and amplitude stabilization within 0.1%. To achieve this goal, the designed circuitry is divided into two parts: the signal reference source and the amplifying stage. Several different types of crystal oscillators were tested, and the impedance issues of matching the reference signal into the amplifying stage are studied. The circuit testing of the amplifying transistors is undertaking, in order to detect the proper transistors as the power amplifier to further amplifies the reference signal. In addition, the use of high power bipolar junction transistors and modification of the transformer should provide higher driving voltage, which is useful for mass filtering applications, particularly for high m/z ions generated by MALDI. The optimized solution of matching the final output signal to the quadrupole while maintaining the performance will be studied.