在种类繁多的通信、雷达及探测等系统中，滤波器是关键核心器件之一。现有滤波器综合技术经历了百年的发展，在生产实践中发挥了重要的作用，但仍然存在不足，无法适应当前复杂频率划分的要求。本项目将针对滤波器综合技术开展深入的研究。我们已经提出一种新型滤波器综合技术-直接综合技术(Direct synthesis techniques)，能够有效得涵盖现有综合技术，又能大大扩宽滤波器的应用范围，实现更为复杂的频率响应。一方面，具有复杂频率响应的滤波器综合是一个具有挑战性的逆问题，本项目将继续探索它们的有效集总参数网络实现。另外一方面，将积极探索直接综合技术在其它形式滤波器中的应用，包括分布参数滤波器如波导滤波器或微带滤波器、有源RC滤波器及数字IIR滤波器等等，进一步扩宽直接综合技术的应用范围。本项目完全具有可行性，已经申请发明专利保护，能进一步开发成具有独立知识产权的商业化软件，为国家的经济建设服务

As ones of key components, filters play an important role in various communication, radar or detection systems. Conventional filter synthesis techniques have undergoing more than one-hundred years development and playing great role in practice. However, there are still many serious problems with them. For example, they are unable to meet the requirement of complicated frequency allocation. This project will focus on the development of novel filter synthesis techniques. We have proposed some new ones, i.e., direct synthesis techniques (DSTs). Conventional synthesis techniques can be covered by the DSTs. Simultaneously, the DSTs can greatly extend the application scope of filters and might realize complicated frequency response that conventional filter synthesis techniques are unable to do. On one hand, how to realize filters with complicated frequency response is an inverse problem. To find out appropriate lumped-element LC networks for realization will be conducted in this project. On the other hand, application of the DSTs in other filter realization forms will also be done, such as active RC filters, digital IIR filters and distributed-element filters such as waveguide or microstrip filters. The research proposition in this project is quite feasible. Some ideas have been protected through some authorized patents. In the future, advanced softwares based on the DSTs can be developed to serve for industry.