Microstrip Butler Matrix with Bandpass Filtering Characteristics Based on Uniform Impedance Resonators

Abstract

The invention discloses a microstrip line Butler matrix provided with a bandpass filtering characteristic and based on uniform impedance resonators. The microstrip line Butler matrix comprises four half-wavelength uniform impedance resonators, two input end feed line heads, two output end feed line heads and four port feed lines. Each resonator is electrically or magnetically coupled with another two resonators, and a phase shift characteristic is realized by means of the combination of electric coupling and magnetic coupling paths. According to the invention, 3dB couplers are replaced by the uniform impedance resonators, the structure is simple, and the bandpass filtering characteristic is realized; the phase shift characteristic is realized by means of the combination of electric coupling and magnetic coupling paths, a phase shifter is omitted, a relatively good isolation degree is ensured, and the size of the circuit is substantially reduced; in addition, the Butler matrix is of the microstrip structure, the weight is light, the cost is low, the industrial batch production is facilitated, and the Butler matrix has the advantages of simple structure, easy design and low manufacturing cost.

Description

technical field [0001] The invention relates to the technical field of a Butler matrix in the form of a microstrip line, in particular to a Butler matrix of a microstrip line with band-pass filtering characteristics based on a uniform impedance resonator. Background technique [0002] Due to the rapid development of wireless communication in recent years, whether it is the popularization of 3G technology, the popularity of the Internet of Things or the arrival of 4G, it marks that wireless technology will usher in a peak period of vigorous development. On the other hand, with the rapid development of electronic information, people have higher and higher requirements for communication quality, and problems such as multipath fading and interference between channels are becoming more and more important. At present, the main technology to solve these problems is to use the beam-switching smart antenna, and the Butler matrix, as an important part of the beam-switching smart anten...

AI Technical Summary

Problems solved by technology

At the same time, in practical applications, in order to suppress the spurious frequency of the transmission signal and the intermodulation interference of the amplifier, it is usually necessary to cascade a bandpass filter, which will increase the size of the circuit

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