Butler matrix structure for beam-forming network

Abstract

The invention discloses a Butler matrix structure for a beam-forming network, which is provided with a plurality of wave beam ports and a plurality of antenna array ports, wherein the plurality of wave beam ports are used for receiving corresponding input radio frequency signals; the plurality of antenna array ports are used for outputting coherent signals to a plurality of corresponding antenna array units; the plurality of wave beam ports for receiving the corresponding input radio frequency signals correspond to at least one antenna wave beam pattern responding to the corresponding input radio frequency signals; and the plurality of wave beam ports and the plurality of antenna array ports are mutually connected by a network in between consisting of a plurality of coupling power divider units and a plurality of phase shifter units. The structure is etched on a three-layer printed circuit board and has the advantages of small volume, wide bandwidth range, excellent consistency and stability, high insulation and the like.

Description

[technical field] [0001] The invention relates to a Butler matrix beamforming network of a multi-beam antenna, and more particularly relates to a multi-layer PCB board structure of a 2X4 Butler matrix with high isolation. [technical background] [0002] Multi-beam antennas were mostly used in satellite communications in the early days, but with the rapid development of mobile communications, they are facing problems such as insufficient spectrum capacity. Multi-beam antennas are used in the field of cellular mobile communications to increase network capacity due to their directional pattern characteristics that can generate multiple beams at the same time. [0003] The Butler matrix is ​​the key structure for generating multiple beams. The 2X4 Butler matrix of the present invention can connect four antenna arrays and generate two different beams at two beam ports. The Butler matrix design includes a power division unit and a phase shift unit, wherein the power division unit...

AI Technical Summary

Problems solved by technology

[0004] First of all, the bandwidth characteristics of a single bridge are not good, especially the isolation bandwidth is poor. For example, under the entire operating frequency of the antenna array, the isolation of the bridge is generally only higher than 20dB;

[0005] Secondly, the above scheme also has phase-shift extension lines, and crossing of signal lines is common, resulting in large size and inconvenient processing

[0006] Chinese Patent Publication No. CN101227216 discloses a new type of Butler matrix, but its biggest advantage is only to eliminate the intersection of signal lines, but it also has the disadvantages of narrow isolation bandwidth and large size.

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