Butler matrix

Butler matrix

An electronic phasing device by which the signals from 2n separate elements of an array are combined with their correct relative phases to produce 2n outputs, each of which corresponds to a main lobe (see antenna) pointing in a different direction.
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Performance analysis in terms of transmit beampattern, SINR, and direction of arriving is then evaluated, and we give example of FDA using 4 x 4 Butler matrix for communication application.
Chang, "Dual-band switched beam array fed by dual-band Butler matrix," Electronics Letters, vol.
The Butler matrix is a corporate multiple beam feed, whereas Blass and Nolen matrices exploit the series feed method.
Rahimian, "Enhanced RF steerable beam-forming networks based on Butler matrix and Rotman lens for ITS applications," IEEE Region 8 Int.
In [22], the optimum design for 4 x 4 planar Butler matrix array antenna was given for 5 GHz WLAN only.
It consists of a Butler matrix and a frequency-agile antenna array.
The multi-beam antenna design used by both Motorola and TRW use a two-dimensional Butler matrix beam-forming network to produce a pincushion footprint display within each coverage area.
Multiple beam arrays generally use beamforming networks, such as the Butler matrix or Rotman-Gent lens, to allow the aperture to transmit or receive power in several directions.
One way to implement MBA is using an antenna array fed by a multiple beam forming network such as Blass matrix [3], Nolen matrix [4], Rotman lens [5], and Butler matrix [6].
The Butler matrix is a passive network with [2.sup.n] inputs, [2.sup.n] outputs, [2.sup.n-1] [log.sub.2] [2.sup.n] hybrid couplers, crossovers and phase shifters [8].
The Butler matrix is a well-known implementation of such an orthogonal BFN [13].