Adaptive Microwave Filters and Multiplexers for Communication Systems

多频段微波系统的使用正在增加，特别是在蜂窝网络中。今天的许多手机可以在多个频段上传输不同类型的编码信号。在这些信号的通信中，射频滤波器是必不可少的设备。通过适当的多带滤波设计，可以制作出一个双终端设备，对手机或基站使用的多个频段进行所需的滤波。这减少了滤波器的数量和总尺寸，并且消除了对每种类型的传输信号的开关和多芯片组的需要。 通过实现自适应滤波结构，可以提高微波系统的频谱效率。传统上，开关滤波器组被用来实现这种类型的架构。可调多带滤光器允许根据微波系统的需要分配带宽。自适应双工器和多路复用器的设计将进一步为微波通信系统提供灵活性。可调多带滤波器和可调多路复用器提供的滤波可以相应地进行调整，以满足带宽需求。自适应设备将被开发、设计、制造和表征。在考虑损耗和调谐范围的同时，还将表征它们的线性度性能。将开发计算机辅助设计算法来控制这些自适应滤波器和多路复用器的调谐。 该研究项目的主要目标是开发、制造和表征多频段微波滤波器，开发、制造和表征新型自适应多频段微波滤波器，开发、设计、制造和表征自适应复用器，表征自适应滤波器和复用器的线性性能与频率、损耗和调谐范围的函数关系，以及开发计算机辅助设计程序来确定所制造的滤波器和复用器的最佳调谐状态。

The use of multi-band microwave systems is increasing, especially for cellular networks. Many cell phones today can transmit different types of coded signals over multiple frequency bands. Radio frequency filters are essential devices in the communication of these signals. With a proper multi-band filter design, a two terminal device can be made that performs the needed filtering for the multiple frequency bands used by a cell phone or by base stations. This reduces the amount and total size of the filters and eliminates the need for switches and multiple chip sets for each type of transmitted signal. The spectral efficiency of a microwave system can be improved by implementing adaptive filtering architectures. A switched filter bank has traditionally been used to achieve this type of architecture. Tunable multi-band filters allow for bandwidth to be assigned as needed by the microwave system. The design of adaptive duplexers and multiplexers will further offer flexibility into the microwave communication system. The filtering provided by tunable multi-band filters and tunable multiplexers can adapt correspondingly to satisfy the demand in bandwidth. The adaptive devices will be developed, designed, fabricated, and characterized. Their linearity performance will also be characterized while considering their loss and tuning range. Computer aided design algorithms will be developed to control the tuning of these adaptive filters and multiplexers. The main goals of this research program are to develop, fabricate and characterize multi-band microwave filters, to develop, fabricate and characterize novel adaptive multi-band microwave filters, to develop, design, fabricate and characterize adaptive multiplexers, to characterize the linearity performance as a function of frequency, loss and tuning range for the adaptive filters and multiplexers, and to develop computer aided design programs for determining the optimum tuning states for the fabricated filters and multiplexers.