Research And Design Of Microstrip UWB Bandpass Filters

Recently, with the rapid development of the wireless communication technology and multimedia business, UWB technology has got more concern in the world. With the advantages of rapid transmission speed, low power dissipation, good confidentiality and anti-interference, UWB system has wide application prospect and huge market value. As one of key components in the system, the UWB filter directly affects the performance of the system.The main work in this paper is study and design of UWB bandpass filters. Firstly, the basic theory and design methods of the classical filters are reviewed briefly. Meanwhile the UWB filters design flow and method, include the equation is introduced. Secondly, based on interdigital coupled line structure and multiple mode resonator structure, the bandpass filters with wide stopband are designed and analyzed.As wide application of wireless technology, the interference problem becomes distinct.In order to avoid the frequency interference, two filters with notch-band are designed. Finally, for better performance, filters with both wide stopband and notch-band characteristics are designed.The primary work in this paper is generally as following:1. Design a filter with dumbbell stubs based of MMR structure, realize the wide stopband.2. Utilizing the even-odd mode analysis method, design a filter with K-shaped structure, that has good in-band and out-of-band performance.3. Coupled folded SIR structure can introduce a notch-band andλg0 / 4 short-circuit stub is used to form a bandpass filter, combine the two structures, an UWB bandpass filter with a notch-band is designed.4. A filter with two notch-bands is designed using interdigital coupled line with open-circuit stubs structure and spiral line structure.5. Synthesis and design filters with wide stopband and notch-band.