ULTRA-WIDEBAND 170 AND 240 GHZ CW SOURCE SWEEPING SYSTEMS

超宽带 170 和 240 GHZ CW 源扫描系统

• 批准号: 8363967
• 负责人: CURT R DUNNAM
• 金额: $ 0.78万
• 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/8363967
• 关键词: Area; Custom; Development; Diagnostic; Electron Spin Resonance Spectroscopy; Evaluation; Frequencies; Funding; Grant; Investigation; Measurement; Methods; National Center for Research Resources; Output; Performance; Phase; Predisposition; Principal Investigator; Procedures; Research; Research Infrastructure; Resources; Services; Source; Staging; System; Techniques; Technology; Testing; United States National Institutes of Health; Work; base; cost; design; design and construction; improved; instrumentation; millimeter; operation; programs

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. Verification and tuning procedures related to bridge setup for ESR spectroscopy are, in general, greatly facilitated by swept-frequency measurement of transmitted/reflected power. Swept-frequency evaluation methods are especially useful in the millimeter-wave regime, and even more so when quasioptical techniques are employed, mainly due to the numerous interacting adjustments and enhanced quasioptical bridge susceptibility to extra-path reflections. As useful as swept measurement capability is, off-the-shelf test and measurement instrumentation providing phase-locked swept-frequency capability at even the lower millimeter-wave regime (i.e., below 100 GHz) is inordinately expensive and, above that frequency range, appears to be available only on an even more expensive custom-built basis. For this reason, ACERT had not previously invested in millimeter-wave swept-measurement capability for its 170 and 250GHz c.w. spectrometer bridges. Last year, ACERT acquired significantly improved millimeter-wave sources of center frequencies at 170 and 240 GHz for its high-field c.w. quasioptical ESR spectrometers. These units generate approximately 12dB more output power than the previous c.w. sources and provide phase-locked operation over a relatively broad frequency range of fc ¿ 5 GHz. In view of the significantly higher output power available from these sources, an extensive program of bridge and resonator design upgrades was undertaken for optimized bridge operation in inductive-reflection mode. During the course of this development work, it became evident not only that swept-frequency measurement capability would be indispensable, but also, conveniently, that these extended-range c.w. sources might be pressed into service for such incidental use. Our work to date in this area has resulted in an interim 170GHz swept-frequency system which has proven extremely useful in the setup and fine-tuning of the H.F. reflection bridge. We have found that, although the swept output power is not actively leveled, the source multiplier stage bias levels may easily be tuned to provide better than 1.2 dB flatness at fc ¿ 1.0GHz and approximately 3dB over the entire source tracking range from 165 to 175GHz. This performance level is more than sufficient for general bridge and resonator tuning procedures. Given the encouraging results thus far, we plan to continue this project over the coming year with similar investigation of the new 240GHz tracking c.w. source for swept measurements. During the coming year, we plan to continue with the design, construction, installation and programming of a simplified operator interface for switching between normal c.w. operation and the swept-frequency diagnostic modes.

该副本是利用资源的众多研究子项目之一 由NIH/NCRR资助的中心赠款提供。对该子弹的主要支持 而且，副投影的主要研究员可能是其他来源提供的 包括其他NIH来源。列出的总费用可能 代表subproject使用的中心基础架构的估计量， NCRR赠款不直接向子弹或副本人员提供的直接资金。 通常，与ESR光谱的桥梁设置有关的验证和调整程序通常是通过扫描频率测量的传输/反射功率来制备的。扫描频率评估方法在毫米波状态中特别有用，甚至在采用准电极技术时，主要是由于大量相互作用的调整和增强的准桥易感性对额外路径反射的敏感性。尽管有用的测量能力是有用的，但即使是下部锁定的扫描式频率能力，即使是较低的毫米波状态（即，低于100 GHz）的现成测试和测量仪器，而且频率高于该频率，似乎仅以更昂贵的定制基础可用。因此，Acert以前没有以170和250GHz C.W.投资毫米扫描测量能力。光谱仪桥。 去年，ACERT的高田C.W.获得了170和240 GHz的中心频率的明显改善。准自动ESR光谱仪。这些单元比以前的C.W.产生的输出功率约为12dB。来源并提供相对广泛的FC»5 GHz的相锁操作。鉴于这些来源可获得的显着更高的输出功率，因此进行了广泛的桥梁和谐振设计升级程序，以在电感反射模式下优化桥梁操作。在这项开发工作的过程中，不仅证明扫描频率的测量能力是必不可少的，而且也很方便地表明这些扩展范围C.W.来源可能被迫用于此类偶然使用。 迄今为止，我们在这一领域的工作导致了一个临时170GHz扫描频率系统，事实证明，在H.F.反射桥的设置和微调中非常有用。我们发现，尽管没有积极地升级扫描的输出功率，但很容易调整源乘数阶段偏置级别，以便在FC€1.0GHz时提供优于1.2 dB平面度，在整个源跟踪范围内，在165至175GHz的整个源跟踪范围内提供了大约3DB。对于通用桥梁和谐振器调整程序，该性能水平足以满足。鉴于到目前为止的令人鼓舞的结果，我们计划在来年继续进行该项目，并通过新的240GHz跟踪C.W.进行类似的投资。扫描测量的来源。在来年，我们计划继续进行简化操作员界面的设计，构造，安装和编程，以在普通C.W.之间切换。操作和扫描频率诊断模式。