The Applied Study Of Filter Using Rectangle Ring Microstrip Resonators

In recent years, the requirement toreceive/radiation circuit of radiation frequency(RF) systems is higher and higher with the high development of commercial wireless communication in business. As one of the important microwave components, the microwave filters also broadly be used in the systems. microwave filters play important roles in many RF/microwave applications. So developing high performance and miniaturized microwave filter has practical significance.First of all, this article introduced the theory and characteristic of the single-mode rectangle ring resonators and respectively carries on the frequency characteristics of the analysis to the direct coupling rectangle closed-loop resonators and the parallel coupling rectangle ring resonators, results showed that the two resonators have a good selective characteristic for the frequency, then, this article also introduced a dual-mode rectangle ring resonator fed by quarter-wavelength side-coupled lines, analyzing the configuration and the frequency characteristics of this rectangle ring resonators, on this basis respectively carries on the resonance characteristics of the analysis to the rectangle ring resonator with identical coupled lines and the rectangle ring resonator with nonidentical coupled lines. Results showed that the two resonators have a good selective characteristic for the frequency. Finally, design a band-pass filter, the idea was to replace one of the coupled line resonator of a classical third-order coupled lines band-pass filter with dual-mode rectangle ring resonator. Compare with the classical third-order coupled lines band-pass filter this band-pass filter have a better frequency characteristic. Also have a good out-of-band response.