The Design Of Coaxial Filter And UWB Microstrip Filter

Earlier period in the telecommunication development, the filter is very important in the electric circuit, and develops continuously along with the technical development. In modern telecommunication equipments and kinds of control systems, the filter application is extremely extensive. In all the electronic parts, the filter is used more extensive and the technique is more complicated. The quality of the filter determines the quality of product directly, the research and the production of filter attach great importance.This paper starts from the theory analysis of a network of both ends of the filter, introducing the basic theory and the traditional design methods of the filter. This paper starts from the theory analysis of a network of both ends of the filter, introducing the basic theory and the traditional design methods of the filter. A coaxial filter is designed according to this theory. This filter is a cuboid. And compose by 3 resonators; those 3 resonator is coupled by 2 coupler. Both the resonator and coupler is cylinder. And then use of simulation software-HFSS to emulate and optimize this filter. With the assistance of simulation software, the process of design filter becomes accurate, fast and practical.Then design a microstrip filter, this filter was developed on a microstrip line and presented in this letter for use in wireless communication applications. The basic filter is composed of five short-circuited stubs separated by non-redundant connecting lines that contribute to the filter selectivity as well. In addition, a cross-coupling between the feed lines (input and output) was introduced which generated new pairs of attenuation poles at each side of the passband. As a result, the filter exhibited extremely sharp rejection skirts around the target passband without the need for increasing the number of transmission line sections. For obtain require of designing, used of ADS to emulate and optimize this filter. For approve those target, and also to prove this theory, fractured a UWB micorstrip filter. Attribute to existing test condition and material condition, the filter is to be debased center frequency and increased the highness base band. Then the result of testing is turn to be the same with the theory.At the end of this thesis the comparison the two filter for designing process and simulation result and difference of the two simulation software are made. Then analyze and discuss the result of simulation. Last analyze the difference of the practicality and the simulated result, and analyze the difference of the simulated result and the test result.