Electromagnetic hybrid coupling-based micro-strip duplexer

Abstract

The invention discloses an electromagnetic hybrid coupling-based micro-strip duplexer, which comprises a double-faced copper-plated micro-strip board, wherein two filters with controllable passband frequency and bandwidth, a first port feeder, a second port feeder, a T-joint, a first port, a second port and a third port are formed on one surface of the double-faced copper-plated micro-strip board, and a copper-plated grounding plate is arranged on the other surface of the double-faced copper-plated micro-strip board; the two filters are respectively formed by three quarter-wave micro-strip resonators coupled with one another, a connection part at one end of the three resonators is provided with a grounding hole, and electric coupling is generated between every adjacent resonators in each filter. According to the duplexer, electric coupling is introduced on the basis of the original magnetic coupling, so that the bandwidth of the duplexer can be changed freely by adjusting the strength of the magnetic coupling and the electric coupling, and the improved filters can generate a plurality of transmission zero points near the upper and lower cut-off frequencies, so that mutual influence between the two filters can be reduced through adjusting the positions of the zero points.

Description

technical field [0001] The present invention relates to the technical field of frequency division duplexing, in particular to a microstrip duplexer based on electromagnetic hybrid coupling. 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. Today's wireless communication systems are basically duplex systems. For time-division duplex, the problem can be solved by arranging reception and transmission in different time slices. For frequency-division duplex, in order to reduce the number of antennas, it is necessary A special device is designed to make electromagnetic waves of different frequencies share an antenna without causing mutual interference. Such a device is a duplexer. The miniaturized, low-cost, low-loss, high-isolatio...

AI Technical Summary

Problems solved by technology

These duplexers have their own advantages and disadvantages. For example, the waveguide duplexer has been used for the longest time and is the most mature. It has low loss and high operating frequency, but it is large in size, high in cost, and difficult to tune; The loss is very small, and the stability is high, and the shielding is good, but in the mobile communication frequency domain, its volume is still too large; although the dielectric duplexer realizes the miniaturization of the duplexer, the cost is too high; SAW duplexer The device can achieve frequency characteristics with arbitrary precision, and is small in size, good in design flexibility, and high in reliability, but its disadvantages are high cost, large loss, and low high-frequency withstand power

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