Butler matrix beamforming network with arbitrary phase difference between output ports

Abstract

The invention discloses a butler rectangular wave beam formation network with arbitrary phase difference among output ports. The butler rectangular wave beam formation network comprises four input ports, four output ports, four arbitrary output phase bridging directional couplers, two crossed bridging directional couplers, four terminal open-circuit bridging directional coupling lines and four phase shift lines, wherein phases of the four output ports are determined by phases of the four arbitrary output phase bridging directional couplers and four phase shift lines. The Butler rectangular wave beam formation network with arbitrary phase difference among the output ports is achieved by employing the arbitrary output phase bridging directional couplers, and the wave beam pointing flexibility of an antenna array is improved; by combining the crossed bridging directional couplers, the terminal open-circuit bridging directional coupling lines and the phase shift lines, the butler rectangular wave beam formation network with relatively small volume is achieved; and the rectangular wave beam formation network has the advantage of low cost, is easy to process and is suitable for wide promotion.

Description

technical field [0001] The invention belongs to the field of microwave antennas, in particular to a Butler matrix beam forming network with arbitrary phase difference between output ports. Background technique [0002] The role of the beamforming network is to provide fixed amplitude and phase to the element antennas in the antenna array to achieve different beam scanning angles. Beamforming array antennas have been developed rapidly in both civilian and military fields. A common implementation of beamforming networks is the use of Butler matrices. The traditional Butler matrix is ​​a symmetrical structure consisting of directional couplers, crossover circuits and phase shifters. For example: a 4×4 butler matrix contains four input ports and four output ports, and one of the input ports is excited to obtain phase differences between output ports with equal amplitude and fixed distribution. The traditional butler matrix has a phase difference of ±45° and ±135°. By connect...

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Problems solved by technology

[0003] However, the traditional Butler matrix can only achieve phase differences of ±45° and ±135°, resulting in the antenna array beam pointing to four fixed directions

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