MODULATION DRIVER WIDEBAND POWER DEVELOPMENT PROJECT

调制驱动器宽带电源开发项目

• 批准号: 8363959
• 负责人: CURT R DUNNAM
• 金额: $ 0.05万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8363959
• 关键词: Amplifiers; Automobile Driving; Biology; Chemistry; Clip; Detection; Development; Exhibits; Frequencies; Funding; Generations; Grant; Heating; Hybrids; Laboratories; National Center for Research Resources; Noise; Output; Principal Investigator; Research; Research Infrastructure; Resources; Services; Signal Transduction; Source; Technology; Testing; United States National Institutes of Health; Width; cost; design; electric impedance; magnetic field; millimeter; operation; voltage

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. High-level modulation of the B0 external magnetic field is desirable in millimeter-wave ESR studies over a wide range of problems in chemistry and biology where the linewidths are often large (100G) given that the signal to noise ratio (SNR) is proportional to the modulation amplitude (mod amp) for mod amps less than or approaching 1/5 of the line width. For high-level modulation of B0 in our 170 and 240 GHz spectrometer bridges, we have designed an extremely wideband power amplifier which is capable of stably driving off-tuned resonant loads which exhibit a large reactive component. Conventional audio-frequency power amplifiers, which are sometimes pressed into service as modulation coil drivers, are not well-suited for this type of service. Generally, they are inefficient and poorly characterized in the region above approximately 50 KHz, especially when driving highly capacitive or inductive impedances. The ACERT modulation amplifier design, in contrast, overcomes those limitations. It operates in either constant-current (CC) or constant-voltage (CV) modes, and can produce up to 50 watts of output power at frequencies from d.c. to 150KHz. Utilizing a commercially-available h.v. hybrid operational amplifier, this wideband power driver design is simple, low-cost and robust, but also features high linearity and stability. Its output section includes provisions for detection and signaling of abnormal output conditions, such as clipping due to, e.g., mistuning of the modulation coil network. Operation in CC mode minimizes amplitude drift in the detected spectrum due to modulation coil self-heating and permits direct modulation with a constant magnetic field generation coefficient, when a fixed input-to-field ratio is required. CV mode permits use of the amplifier in other laboratory applications such as piezoelectric actuator driver for CD-ESR. Having prototyped and tested sections of the modulation driver amplifier, our next step in the project plan is to design a compact package for the complete amplifier and construct several integrated units for HF, and possible CD-ESR use, during the coming year.

该子项目是利用资源的众多研究子项目之一 由 NIH/NCRR 资助的中心拨款提供。子项目的主要支持 并且子项目的主要研究者可能是由其他来源提供的， 包括其他 NIH 来源。 子项目可能列出的总成本 代表子项目使用的中心基础设施的估计数量， NCRR 赠款不直接向子项目或子项目工作人员提供资金。 B0 外部磁场的高水平调制在毫米波 ESR 研究中适用于化学和生物学中的各种问题，其中线宽通常很大 (100G)，因为信噪比 (SNR) 与调制放大器的调制幅度（调制放大器）小于或接近线宽的 1/5。 为了在 170 和 240 GHz 光谱仪电桥中对 B0 进行高级调制，我们设计了一种超宽带功率放大器，能够稳定驱动具有较大电抗分量的失谐谐振负载。传统的音频功率放大器有时被用作调制线圈驱动器，但不太适合此类服务。一般来说，它们在大约 50 KHz 以上的区域效率低且特性较差，特别是在驱动高电容或电感阻抗时。相比之下，ACERT 调制放大器设计克服了这些限制。它可以在恒流 (CC) 或恒压 (CV) 模式下运行，并且可以在直流到直流的频率下产生高达 50 瓦的输出功率。至 150KHz。利用市售的 h.v.混合运算放大器，这种宽带功率驱动器设计简单、低成本且坚固耐用，而且还具有高线性度和稳定性。其输出部分包括用于异常输出条件的检测和发信号的规定，例如由于调制线圈网络的失调而导致的削波。 CC 模式下的操作最大限度地减少了由于调制线圈自热而导致的检测到的频谱中的幅度漂移，并且当需要固定的输入场比时，允许使用恒定的磁场生成系数进行直接调制。 CV 模式允许在其他实验室应用中使用放大器，例如用于 CD-ESR 的压电致动器驱动器。 在对调制驱动器放大器的各个部分进行原型设计和测试后，我们项目计划的下一步是为整个放大器设计紧凑的封装，并在来年构建多个用于 HF 和可能的 CD-ESR 使用的集成单元。