Terahertz Micromachined Resonator Superstructures

该应用程序有三个不同但相互关联的研究领域。第一种是利用互耦合谐振器设计微波电路的方法。该方法是非常普遍的，可以在很宽的频率范围内使用微波电路中使用的许多不同的技术。第二个领域是使用微机械太赫兹器件在特定的频率和特定的应用中验证新的设计技术。微机械加工必须用于制造精确尺寸的波导，精度低至微米。第三个领域是太赫兹应用的微加工工艺的改进。互耦合谐振器已经被用于制造微波滤波器多年。对于具有传输零点或双频带的更复杂的通带响应，相互耦合变得更加复杂。该建议将这一概念进一步发展，并提出可以使用耦合谐振器或谐振器上层结构来制造整个无源系统。为了证明这一点，作者已经证明了功率分配器和双工器的基础上，这些概念，和拟议的工作是看看天线馈电网络，巴特勒矩阵和滤波器组。该技术可以提供任何中心频率的微波电路设计，在许多领域将是有用的。现在的技术允许以更高的频率构建系统; 2 GHz左右的移动的通信现在已经很普遍，但77 GHz的汽车雷达系统只是在过去几年中才刚刚开发出来，现在在亚毫米波区域100 GHz以上的应用开始出现。1太赫兹及以上的应用被认为对未来系统极其重要。最低损耗的波导结构之一是矩形波导，而这项工作将着眼于微机械波导。这些电路是由多层金属化硅或厚抗蚀剂堆叠而成的。两个层用作引导件的顶部和底部，并且交错层（或多个层）形成中空矩形管的壁。对于300 GHz，这些波导约为800 × 400微米，因此需要进行微机械加工以使它们精确地达到此尺寸。在伯明翰，已经开发出一种可靠、精确的层间粘合技术。将演示滤波器、功率分配器、双工器和三工器等结构。谐振器上层结构也将被配置在波导谐振器中，以产生亚毫米波天线馈电网络、巴特勒矩阵和滤波器组。这包括能够选择性地图案化金涂层的顶部和垂直边缘。这将使过渡到其他传输结构，如共面波导，以及改善层之间的结合的能力。此外，工作将继续发展一种新的电介质波导结构，首先着眼于在抗蚀剂SU 8中嵌入石英纳米颗粒。提供低损耗波导结构将为微波设计者提供另一种电路构造工具。

This application has three distinct but interrelated research areas. The first is a method of designing microwave circuits using inter-coupled resonators. The method is extremely general, and can be used over a wide frequency range with many different technologies used in microwave circuits. The second area is using micromachined terahertz devices to exemplify the new deign techniques at a particular frequency and for a particular application. Micromachining has to be used to make accurate dimensioned waveguides with accuracies down to microns. The third area is the improvement in the micromachining process for the terahertz application.Inter-coupled resonators have been used for many years to make microwave filters. For more complex passpand responses with transmission zeros or dual bands, the inter-coupling becomes much more complex. This proposal takes this concept a stage further and proposes that whole passive systems can be made using coupled resonators or resonator superstructures. To exemplify this the authors have already demonstrated power splitters and a diplexers based on these concepts, and the proposed work is to look at antenna feed networks, Butler matrices and filter banks. The techniques can provide the design of microwave circuits at any centre frequency and will be useful in many areas. Technology is now allowing systems to be constructed at much higher frequencies; mobile communications at around 2 GHz is now commonplace, but car radar systems at 77 GHz have only just developed in the last few years, and now applications are beginning to emerge at above 100 GHz in the submillimetre wave region. Applications to 1 terahertz and above are seen as extremely important for future systems. One of the lowest loss waveguide structures is the rectangular waveguide, and this work will look at micromachined waveguide. The circuits are made by stacking layers of metalised silicon or thick resists. Two of the layers act as the top and bottom of the guide and the interleaving layer (or layers) forms the walls of the hollow rectangular tube. For 300GHz these waveguide are about 800 by 400 microns and micromachining is therefore required to make them accurately at this size. At Birmingham a reliable, accurate techniques for bonding the layers has been developed. Structures such as filters, power splitters, diplexers and triplexers will be demonstrated. The resonator superstructures will be also configured in waveguide resonators to produce submillimetre wave antenna feed networks, Butler matrices and filter banks.Finally work will be done to improve the micromachining process. This includes being able to selectively pattern the top and vertical edges of the gold coating. This will enable transitions to other transmissions structures such as coplanar waveguides as well as the ability to improve the bonding between layers. In addition work will proceed on the development of a new dielectric waveguide structure, initially looking at the embedding of quartz nano particles in the resist SU8. Providing a low loss waveguide structure will give the microwave designer another tool for circuit construction.