Optical Implementation of Butler Matrix for Hardware-Efficient Multiuser Beamforming
IEEE Photonics Journal, 2018 Phased antenna arrays have been used extensively for massive MIMO-based multiuser beamforming to improve both the throughput and power efficiency of wireless communication systems.
Huiyuan Liu +5 more
doaj +1 more source
Flexible Phase Difference of 4 × 4 Butler Matrix without Phase-Shifters and Crossovers
International Journal of Antennas and Propagation, 2019 This paper proposes a new Butler matrix topology. The proposed Butler matrix consists of only four couplers without phase shifters and crossovers. The output phase difference is relatively flexible.
Ke Han, Wuyu Li, Yibin Liu
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A 20-GHz-Band
IEEE Access, 2019 In this paper, a 20-GHz-band 64 x 64 hollow waveguide Butler matrix is proposed. By using two-plane short slot couplers and a modified diagram, a short-axis two dimensional Butler matrix is realized.
Takashi Tomura +5 more
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Broadband Butler matrix with flat coupling
Electronics Letters, 2007 Conventional Butler matrices composed of hybrids, crossovers and phase shifters, are narrowband structures. Presented is a constant coupling and phase shift broadband Butler matrix with a simple structure using novel disk hybrids and improved phase shifters.
S. Zheng, W.S. Chan, S.H. Leung, Q. Xue
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A Low Complexity
IEEE Access, 2019 Beamforming networks such as Butler Matrices are important for multibeam array antenna applications. The challenge for Butler Matrix design is that their complexity increases with the number of ports.
Qingling Yang +7 more
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Generalized One-Dimensional Parallel Switching Matrices With an Arbitrary Number of Beams
IEEE Journal of Microwaves, 2021 This paper introduces a novel family of one-dimensional switching matrices, also known as beamforming networks (BFNs), which can be sized for an arbitrary number of beams.
Jiro Hirokawa, Nelson J. G. Fonseca
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High resolution beam switch antenna based on modified CRLH Butler matrix
Engineering Reports, 2021 A new beam switch antenna based on a composite right/left‐handed (CRLH) Butler matrix is presented and experimentally validated. The CRLH transmission line (TL) is proposed to increase the number of beams.
Reza Karimian +3 more
doaj +1 more source
Wide bandwidth Butler matrix network
Electronics Letters, 1967 Butler matrix networks, used for forming multiple beams from linear aerial arrays, are limited in their bandwidth of operation by their requirement for components with constant values of phase shift over this bandwidth. This letter describes a method for designing such networks for wide-bandwidth operation by employing particular combinations of ...
P.E.K. Chow, D.E.N. Davies
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Ordered Ionic‐Liquid Channels Enable Fast Anhydrous Proton Conduction at up to 240°C for Fuel Cells
Angewandte Chemie, EarlyView.Infiltration of ionic liquids into a composite scaffold comprised of graphene and boron nitride nanosheets functionalised with positively charged polyethyleneimine produces robust proton conducting membranes for the intermediate temperature electrochemical devices.
Mazin Al‐Alawi +8 more
wiley +2 more sources
Miniaturization Design for 8 × 8 Butler Matrix Based on Back-to-Back Bilayer Microstrip
International Journal of Antennas and Propagation, 2014 A low-cost, compact 8 × 8 Butler matrix based on a novel bilayer microstrip configuration is presented and implemented for 4.3 GHz telecommunication application.
Yu Zhai +3 more
doaj +1 more source