The Study And Design Of Microstrip Filter With Loop Circuit

In a modern communication system, in particular, satellite communications and mobile communications systems, the filter performance indicators are demanded increasingly. These technologies of using microstrip line to achieve power coupling / distributor,dividers, mixers, filters and microstrip antenna, are increasing development and maturity. The microstrip filter has the advantages of a small size, easy processing through lithography, easy to compatible with other active circuit components. In addition microstrip filter using different substrate materials can be applied to a great frequency range. Microstrip filter in the modern design of the filter were high hopes.Therefore, in view of the importance of microstrip filter papers on the basis of the loop microstrip filter theoretical analysis, simulation software used by the microstrip ADS posed by the closure loop microstrip filter research and design. This paper presented by the closed circuit loop microstrip,which of the characteristics is small area, simple structure, easy to create. The loop microstrip closed circuit filter is a closed ring and at both ends of a line directly connected, according to central by-line and then the different positions, the closure loop filter in the attenuation of poles are also changing. Through theoretical calculations and simulation of the software ADS, present this loop microstrip closed circuit has filter characteristics. But in the stopband attenuation also not ideal, in order to satisfy the stopband attenuation, as far as possible, but its steep and stopband attenuation also not ideal, in order to satisfy the stopband attenuation, as far as possible, and the steep performance requirements, in the text taken in this circuit in the loop and spur lines to a capacitor that is, so you can make this a closed loop microstrip filter performance improved significantly. Small microstrip filter design is also the hot issues, the text use of shortening the microstrip completed the principle of this loop microstrip closed circuit small.