WM380 (675-700 GHz) Bandpass Filters in Milled, Split-Block Construction
WM380 (675-700 GHz) Bandpass Filters in Milled, Split-Block Construction
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DOI：
10.1109/tthz.2018.2873114
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发表时间：
2018-11-01
影响因子：
3.2
通讯作者：
Hesler, Jeffrey L.
中科院分区：
文献类型：
--
作者：
Koller, Daniel;Bryerton, Eric W.;Hesler, Jeffrey L.
滤波器在射频分析和通信硬件中起着非常重要的作用，可以阻止不需要的信号，限制带宽，衰减谐波分量等。在功率通常较低的毫米波频率波导结构中，虹膜耦合谐振器带通滤波器已被证明非常实用，易于加工。在Virginia Diodes，我们的大部分技术都是使用标准的“分割块”技术构建的，在这种技术中，使用高精度计算机数控铣床从实心金属块中铣削出特征。典型的加工公差在+/-5-10 μ m的量级。类似于200 GHz的这种滤波器的构造已经是常规的，但是将操作推进到太赫兹范围需要特殊的考虑。这里描述的是具有675-700 GHz通带的用于500-750 GHz波导频带的WM 380（WR 1.5）滤波器。该滤光片是640 GHz外差式偏振计的概念验证，该偏振计是小型企业创新研究（SBIR）资助的一部分，旨在为NASA计划的气溶胶、云和生态系统使命开发技术。从一开始，过滤器的设计和优化都是假设结构将被铣削，因此需要所有内部特征适应现有机床的有限半径。这种过滤器的构造需要仔细注意加工公差，以便能够将铣床推到+/-2.5 μ m或更好的绝对极限。一批过滤器的测量结果显示，并比较模拟，以说明如何以及这些过滤器可以。此外，滤波器可以通过简单的机械装置进行调谐，并且给出了数据以说明滤波器可以多么容易地进行调整。滤波器拓扑结构的其他修改，以简化加工，并允许其他建设技术被利用也证明。最终，应该有可能推动分裂块技术来制造虹膜耦合谐振器滤波器，用于远超过1 THz的频率。
Filters play an invaluable role in RF analysis and communications hardware, blocking unwanted signals, limiting bandwidth, attenuating harmonic components, etc. In waveguide construction for mm-wave frequencies, where the powers are generally low, the iris-coupled-resonator bandpass filte has proven to be very practical and amenable to easy machining. At Virginia Diodes, much of our technology has been constructed using standard "split-block" techniques, in which high-precision computer numerical control milling machines are used to mill out the features from solid blocks of metal. Typical machining tolerances are on the order of +/-5-10 mu m. Construction of such filter to similar to 200 GHz has been routine but pushing the operation into the Terahertz regime requires special considerations. Described here is a WM380 (WR1.5) filte for the 500-750 GHz waveguide band having a passband of 675-700 GHz. The filte is proof of concept for a 640 GHz heterodyne polarimeter, designed as a part of a Small Business Innovative Research (SBIR) Grant to develop technology for NASA's planned Aerosol, Cloud, and Ecosystems mission. From the very beginning, filte design and optimizations were carried out assuming the structure would be milled, hence necessitating that all internal features accommodate the finit radii of available machine tools. Construction of this filte required careful attention to machining tolerances to be able to push the milling machines to their absolute limits of +/-2.5 mu m or better. Measured results of a batch of f lters are shown and compared to simulations to illustrate just how well these filter can be made. Furthermore, the f lters can be tuned by simple mechanical means and data are presented to illustrate how easily the f lters can be adjusted. Additional modification to the filte topology to simplify machining, and allow other construction techniques to be utilized are also demonstrated. Ultimately it should be possible to push the split block technology to manufacture iris coupled resonator filter for use at frequencies of well over 1 THz.