Low-Complexity High-Bandwidth Multiport Matching Networks for Coupled Loads

发射和接收信号的无线设备通常具有天线元件作为其设计的一部分。 这些天线元件需要与它们所连接的射频放大器“匹配”，就像音频扬声器需要与放大器匹配以优化音乐系统的声音一样。 当在紧凑设备中存在许多天线时，匹配电路可能是复杂的，因为这些天线彼此交互和耦合。 由于这种耦合，与一个天线的任何连接都会干扰与相邻天线的连接。 因此，当放大器与天线间隔很近时，将放大器连接到天线的问题需要仔细考虑和系统的电路设计过程。 现有的设计往往是复杂的，非系统的，并且难以实现在一个紧凑的方式，因此，很多发射机的功率损失到一个不良的匹配。 这项研究着眼于简单的系统电路设计，实现了良好的匹配，在广泛的发射机频率。 由于无线设备被要求同时在多个频带中以高数据速率操作，因此这种电路可以在现有频带以及下一代频带中的无线连接方面产生巨大的改进，在下一代频带中，对天线数量、数据速率和设备性能的要求预计将更加极端。 在这一努力下开发的低复杂性，高带宽网络的理论和实验验证预计将对低成本高性能设备的性能产生重大影响，并造福于整个社会，包括在个人通信和医疗遥测中的应用。 这项工作也有显着的教育效益，因为它将培养跨学科的研究生在通信，电路和微波工程的主题组合。这项研究工作提倡低复杂度高带宽多端口匹配网络的设计和分析，以补偿射频发射机，接收机和电路中的耦合。 插入独立源和耦合负载之间的理想多端口匹配网络通过消除反射功率以及从一个源通过负载传输到另一个源的功率来补偿耦合。在这种网络的设计限制中，复杂性和带宽通常是最重要的，特别是对于紧凑的宽带无线通信设备。 这些限制还没有得到很好的研究，这方面的努力包括一个综合的双管齐下的微波和毫米波匹配网络中的这些问题的探索。 第一个方面使用网络理论分析来探索适用于任何负载结构的系统的、统一的设计方法。这项工作还寻求标准化的限制，以衡量网络在复杂性和带宽方面的性能。第二个方面结合了一个实验程序来验证和通知匹配网络的设计和优化中所做的建模选择。 实际问题，如不希望的寄生耦合和电磁不连续性在分布式电路实现将被检查。 特别感兴趣的是具有集总和分布式射频元件的微波（2.4 GHz）和毫米波（60 GHz）频率，以及对简单模块布局的强调。 这项工作是变革性的，因为它将为适用于紧凑型射频设备的多端口匹配网络的复杂性和带宽提供一套全面统一的指标，设计标准和方法。

Wireless devices that transmit and receive signals usually have antenna elements as part of their design. These antenna elements need to be "matched" to the radio-frequency amplifiers they are connected to, much in the way audio speakers need to be matched to amplifiers to optimize the sound of a music system. Matching circuits can be complicated when there are many antennas in a compact device since these antennas interact and couple with each other. Because of this coupling, any connection with one antenna disturbs the connections with neighboring antennas. Hence, the problem of connecting amplifiers to antennas when they are closely spaced requires careful consideration and a systematic circuit design process. Existing designs tend to be complicated, non-systematic, and difficult to implement in a compact manner; as a result, much transmitter power is lost to a poor match. This research effort looks at simple systematic circuit designs that achieve a good match across a wide range of transmitter frequencies. Since wireless devices are being asked to operate in many bands simultaneously and with high data rates, such circuits can yield great improvements in wireless connectivity in existing frequency bands as well as next-generation bands where the demands on the number of antennas, data rates and device performance are expected to be even more extreme. The theory and experimental validation developed under this effort for low-complexity, high-bandwidth networks is expected to have significant impact on the performance of low-cost high-performance devices, with benefit to society at large, including applications in personal communications and medical telemetry. The effort also has significant educational benefits since it will train an interdisciplinary mix of graduate students in topics within communications, circuits, and microwave engineering. This research effort advocates the design and analysis of low-complexity high-bandwidth multiport matching networks to compensate for coupling in radio-frequency transmitters, receivers, and circuits. The ideal multiport matching network inserted between independent sources and coupled loads compensates for the coupling by eliminating both reflected power and also power transferred from one source through a load to another source. Among the design limitations of such networks, complexity and bandwidth are usually the most important, especially for compact wideband wireless communication devices. These limitations have not been well studied, and this effort includes an integrated two-pronged exploration of these issues in microwave and millimeter-wave matching networks. The first prong uses network-theoretic analyses to explore systematic, unified, design methods that work for any load structure. The effort also seeks standardized limits against which network performance in both complexity and bandwidth can be measured. The second prong couples an experimental program to both validate as well as inform the modeling choices made in the design and optimization of the matching networks. Practical issues such as undesired parasitic coupling and electromagnetic discontinuities in distributed circuit implementations will be examined. Of particular interest are the microwave (2.4 GHz) and millimeter-wave (60 GHz) frequencies with both lumped and distributed radio-frequency components, and an emphasis on simple module layouts. The effort is transformative because it will offer a comprehensive unified set of metrics, design criteria, and methodologies for complexity and bandwidth of multiport matching networks applicable to compact radio-frequency devices.