MILLIMETER-WAVE SOURCES MEASUREMENT AND QUALIFICATION FACILITY

该子项目是利用资源的许多研究子项目之一 由NIH/NCRR资助的中心赠款提供。次级项目的主要支助 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 表示子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 ACERT目前拥有5 c.w. 1个脉冲毫米波源，输出功率约为1 mW ~ 1.2KW。在中心赠款期间，我们越来越需要这些来源的资格，维护和校准服务。为此，我们已经组装了完成这项任务所需的测试和测量仪器，并建立了一个方案，将这些工具应用于它。基本的测量是功率，波长/频率，光谱特性（包括噪声功率），以及脉冲器件的时间响应。为了满足这些需求，我们留出了一个测试区域，在这里可以忠实、快速地再现必要的测量设置。对于我们的准光功率测量，我们依赖于托马斯基廷有限公司的“TK太赫兹”入射功率计系统，当校正波长和光束轮廓时，绝对校准精度约为20%。频率和频谱特性的测量通过泰克492型频谱分析仪，使用一组校准的谐波波导检测器，覆盖20至325 GHz。因为TK功率计对波长相对不敏感，所以它产生校准的功率测量，该功率测量对实际工作频率不高度敏感，也不揭示实际工作频率。另一方面，频谱分析仪产生工作频率的相对准确的测量和实际输出频谱的良好定性测量，但在给定频率下的绝对功率方面校准较差。然而，在两个测量系统之间，可以实现功率、波长/频率和光谱特性的良好互补测量。通过直接观察检测器模式下的适当波导谐波混频器输出来测量时间响应，或者通过解释频谱分析仪观察到的频域频谱来间接测量时间响应。

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. ACERT presently possesses 5 c.w. and 1 pulsed millimeter-wave sources, ranging in output power from approximately 1mW to 1.2KW. During the course of the Center grant period, we have increasingly required qualification, maintenance, and calibration services for these sources. To this end, we have assembled test and measurement instrumentation necessary to accomplish this task, and have established a regimen for applying these tools to it. The fundamental measurements are power, wavelength/frequency, spectral characteristics (including noise power) and, for pulse devices, temporal response. To address these needs, a test area has been set aside where the necessary measurement setups may be faithfully and quickly reproduced. For our quasioptical power measurements, we rely on a Thomas Keating Ltd. "TK TeraHertz" incident power meter system, with an absolute calibration accuracy of approximately 20% when corrected for wavelength and beam profile. Frequency and spectral characteristics are measured by means of a Tektronix model 492 spectrum analyzer, using a set of calibrated harmonic waveguide detectors covering 20 through 325 GHz. Because the TK power meter is relatively insensitive to wavelength, it produces a calibrated power measurement which is not highly sensitive to nor revealing with respect to the actual operating frequency. The spectrum analyzer, on the other hand, produces a relatively accurate measurement of the operating frequency and good qualitative measurement of the actual output spectrum, but is poorly calibrated with respect to absolute power at a given frequency. Between the two measurement systems, however, a good complementary measurement of power, wavelength/frequency and spectral characteristics is achievable. Temporal response is measured either by direct observation of an appropriate waveguide harmonic mixer output in detector mode, or indirectly, by interpretation of the frequency-domain spectrum observed with the spectrum analyzer.