Filtering type cross directional coupler with wide band-pass response and design method

Abstract

The embodiment of the invention discloses a filtering type cross directional coupler with wide band-pass response and a design method. The filtering type cross directional coupler comprises a parallelcoupling line, a parallel open-circuit line, a series transmission line and four matching ports, wherein the parallel coupling line comprises two sections of parallel coupling lines and three sections of capacitor loading parallel coupling lines; the two sections of parallel coupling lines respectively comprise two coupling lines, the three sections of capacitor loading parallel coupling lines respectively comprise two coupling lines and a lumped capacitor arranged between the coupling lines, and the parallel open-circuit line comprises four parallel open-circuit lines; the series transmission lines comprise four series transmission lines; by setting the impedance value of the parallel open-circuit line, two transmission zeros can be generated outside the passband to form a stop band, andthe smaller the characteristic impedance of the parallel open-circuit line is, the wider the stop band is; according to the invention, the passband bandwidth range can be changed by adjusting the characteristic impedance of the series transmission line. Based on the method, broadband, filtering and any power division ratio can be realized.

Description

technical field [0001] The invention relates to the field of filtering couplers, in particular to a filtering type spanning directional coupler with wide-band pass response and a design method. Background technique [0002] With the rapid development of the world's economic level, the demand for miniaturization and integration of wireless communication systems, especially mobile terminal equipment, is becoming more and more obvious. As an important component of a wireless communication system, a coupler has important functions such as signal distribution, signal transmission, and signal isolation. For example, in a radio frequency transceiver system, the coupler acts as a connector for signal transmission and at the same time can send the signal to a display device such as an instrument panel, which is convenient for researchers to interpret. However, the transmission and reception of radio frequency signals in a microwave band are often accompanied by many clutter componen...

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Problems solved by technology

[0003] Since the parallel coupling line directional coupler cannot achieve tight coupling, which limits its wide application in wireless communication systems, most of the existing research is based on the double-branch coupler structure and the ring coupler structure, and the passband is narrow. It cannot meet the broadband needs of the current social communication system; there are few researches to realize the broadband filter coupler, but it is often large in size, complex in structure, and high in processing and manufacturing costs.

Although the cross-directional coupler can achieve tight coupling and has the advantages of low cost, easy processing, and small size, the existing cross-directional coupler cannot achieve wide passband and filtering effect, which further limits its application;

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