The Study Of The Band Pass Filter Of The Microstrip Line

In recent years, along with the high development of wireless communication in business, Microwave RF circuit has been attracted more and more attention and also got many achievements. At the same time, as one of the important microwave components, the microwave filters also developed rapidly in recent years. Especially, the microwave BPF directly influences the performances of the receivers. So, develop high performance, study miniaturized microwave filter is a hot topic in nowadays.With the development of the microwave integrate circuit, especially the MMIC, microstrip is become the mail transmission line to connect the chips, making the microstrip line circuit with distributed parameters more popular in the field of microwave and radio frequency. The technology of using microstrip to design power coupler and divider, frequency divider, mixer, filter, and microstrip antenna has become more mature. Microstrip BPF, with various types and different performances, is one of the filters which are studied in microwave communication. So, as the important of microstrip BPF, based on the theory, this paper will use the software ADS to study and design the microstrip BPF composed microstrip and coupled microstrip.At first, this paper introduces the development history of microwave filters, the function in the microwave communication, the current state of studying the filters and the advanced microwave circuit simulation software HP-ADS. Then analyzed the two-port network of filters and the characteristic of the microstrip, then studied the basic principle of filters, the transition of LP to BP, and the transmission line structure of filters. With the software ADS and the formula which had been proved in this paper, this paper also well design an end-couple BPF, a half-wavelength resonator BPF, an interdigital BPF.The research productions of this paper have much reference value on the filter miniaturization, and improve the efficiency of the filter design. As the finity of the equipment in the working lab, the test of the microstrip BPF has some limitation, and there are also some questions need to be solved in this paper.