Ultra-broadband Microstrip Bandpass Filter Design,

As one of the most important components in the ultra-wideband (UWB) wireless communication system, UWB filter has received increasing attention with the development of UWB wireless communication technology in recent years. This thesis focuses on the research of high performance and compact UWB filters. Some new UWB microstrip bandpass filters are proposed.In Chapter 1, the concept and characteristics of UWB wireless communication system are briefly introduced. The global research backgrounds of the UWB filter are discussed. Finally, research works of this thesis are summarized.In Chapter 2, some theoretical backgrounds related to the research works of this thesis are introduced, including the two-port network theory, as well as the classifications, design principles and the basis parameters of the microwave filters.In Chapter 3, the resonance characteristics of stepped-impedance resonator (SIR) are analyzed by utilizing the transmission line theory. It provides the design basis for the UWB microstrip bandpass filters.In Chapter 4, high-performance and compact UWB microstrip bandpass filters are designed on the basis of the miniaturization property of the SIR. The proposed UWB bandpass filters are found potentially useful in the UWB wireless communication systems.In Chapter 5, the research works of this thesis are summarized. Some potential research directions are also discussed.