DEVELOPMENT OF AN AMPLITUDE AND FREQUENCY STABILIZED HIGH POWER OSCILLATOR

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 在质谱中，多极离子导向器通常由高压振荡器驱动。这种“电源”通常提供频率范围为数百KHz至几MHz的正弦波，振幅小于几KV，以有效地将离子传输通过多极。当DC电势差被施加到具有相反极性RF信号的杆时，四极离子导向器可以作为质量过滤器操作。高稳定性的振荡器需要驱动四极质量过滤器。这项工作（Lin et al.，2009）提出了一种用于保持高功率振荡器的输出频率和幅度的简单、低成本的设计。 目前正在测试一种简单、低成本的设计，其中包括一个“种子”晶体，以提供稳定的参考频率和一个AGC电路，以稳定输出幅度。目标是频率稳定度在30 ppm以内，幅度稳定度在0.1%以内。为了达到这个目的，所设计的电路分为两部分：信号参考源和放大级。测试了几种不同类型的晶体振荡器，并研究了参考信号与放大级匹配的阻抗问题。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来进一步放大参考信号。此外，高功率双极结型晶体管的使用和Transformer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，特别是对于由MALDI产生的高m/z离子。 将研究在保持性能的同时使最终输出信号与四极匹配的优化解决方案。

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.