Design And Research Of The Dual-band UWB Bandpass Filter Based On The Microstrip Discontinuous Structure

In modern technology life, with the rapid development of wireless communication systems, the user number has a sharp increase. Interpersonal communication and communication systems play a significant role. With the current rapid development of communication technology, radio frequency spectrum resources have begun to dry up. This phenomenon has limiting the development of wireless communication technology. There for how to solve the conflict between increasing traffic demand and spectrum resource depletion has become the urgent issue need to be addressed. Under such background, UWB has already proposed and received a lot research. UWB filter for the UWB wireless communication system as one of the most important parts get more and more attention, leading to extensive study and application. The UWB frequency band is too wide (3.1 GHz to 10.6GHz), that in this band it already has some conventional communication such as, the satellite C-band communications and the X-band communications, wireless local area network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX). UWB multi-band filter design method of the traditional cascade of multiple filters, increasing the system size and design costs, and could easily lead to mismatch between components, reducing system efficiency. In recent years, some new design ideas, such as defects in the structure, through-hole structure or multi-layer LTCC structure, although some technical progress, but large-scale integration in the system, with adjustable resistance elements of some key technologies such as lack of. In this paper According to ultra-wideband filter, this paper realize the adjustable Nick stop-band design problems, and put forward the microstrip lines based on discrete double band-pass filter design.Primarily, we analysis the filter based on the CPW/microstrip UWB composite resonator. Then we use Quasi-low-pass methods to optimize this filter. Finally we use the microstrip discrete structure to get the notch-band. Using this method, the notch band has the adjusting range from 5GHz to 8GHz.Secondly, in order to expand the adjusting range, we use MMR filter for further designer. The first step is simplifying this filter. The second step for odd-even mode analysis adopting open stub structure, we finally get stub structure resonance conditions. Using this way the notch band has the adjusting range from 3.5GHz to 9GHz. Further more, in order to expand the range up to 9GHz, we use SIR Structure instead of UIR Structure. Using this method, the notch band has the adjusting range from 3.5GHz to 10GHz.Anyhow through using microstrip discontinuous structure design, we can complete the design very much with double bandpass filter, The final design filter performance meets the design index and actual needs of the project, leading to a wider application space.