Studying And Designing Of SIR Filter

In modern communication system, mobile communication is developed rapidly. With people’s demand increasing, the wireless communication system is moved in the direction of large capacity and high speed. As key components, filters are becoming increasingly important, especially to the front of sending and receiving devices, and their performance will directly affect the performance of the whole system. As science and technology developing, filters of high performance, small size and low cost is the current hot research. This paper mainly studies band pass filter and UWB filter with T-shaped open stubs.This paper starts with a brief introduction to the basic theoretical knowledge of the microstrip line, followed by the development situation of and domestic and foreign research on microstrip filter, and then introduces the development of SIR filter with the theoretical analysis of its structure included.T-shaped open stubs are used to design a simple miniaturized band-pass filter. The use of T-shaped stubs can not only minor its volume with maintaining good performance but reduce its processing difficulty as T-shaped stub line increasing impedance ratio.Then UWB filter based on the T-shaped open stubs loaded with CSRR ring is designed. Because of good band gap characteristics owing to the effect of negative permittivity produced by CSRR, application of CSRR structure on a filter may provide with steep transition edges. The filter designed with not only a good transition band filter but ultra wideband characteristics will be expected to play a vital role in the communication field.According to the theoretical analysis and structural design of this article, actual processing and testing of the filter has proceeded. The experimental results agree well with the simulation results, verifying the correctness of theoretical analysis and the reasonability of the structural design in this article.