Print Email Facebook Twitter InFocus Title InFocus: A spatial coding technique to mitigate misfocus in near-field LoS beamforming Author Myers, N.J. (TU Delft Team Nitin Myers) Heath, Robert W. (University of North Carolina) Date 2022 Abstract Phased arrays, commonly used in IEEE 802.11ad and 5G radios, are capable of focusing radio frequency signals in a specific direction or a spatial region. Beamforming achieves such directional or spatial concentration of signals and enables phased array-based radios to achieve high data rates. Designing beams for millimeter wave and terahertz communication using massive phased arrays, however, is challenging due to hardware constraints and the wide bandwidth in these systems. For example, beams which are optimal at the center frequency may perform poor in wideband communication systems where the radio frequencies differ substantially from the center frequency. The poor performance in such systems is due to differences in the optimal beamformers corresponding to distinct radio frequencies within the wide bandwidth. Such a mismatch leads to a misfocus effect in near-field systems and the beam squint effect in far-field systems. In this paper, we investigate the misfocus effect and propose InFocus, a low complexity technique to construct beams that are well suited for massive wideband phased arrays. The beams are constructed using a carefully designed frequency modulated waveform in the spatial dimension. InFocus mitigates beam misfocus and beam squint when applied to near-field and far-field systems. Subject Antenna arraysArray signal processingArraysBandwidthBeam squintMisfocusMm-waveNear-field communicationPhased arraysspatial FMCWStandardsTerahertzWireless communication To reference this document use: http://resolver.tudelft.nl/uuid:66d4041f-5b78-4006-b9fa-ae18ad9ae01c DOI https://doi.org/10.1109/TWC.2021.3110011 Embargo date 2022-03-13 ISSN 1536-1276 Source IEEE Transactions on Wireless Communications, 21 (4), 2193-2209 Bibliographical note Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Part of collection Institutional Repository Document type journal article Rights © 2022 N.J. Myers, Robert W. Heath Files PDF InFocus_A_Spatial_Coding_ ... orming.pdf 6.62 MB Close viewer /islandora/object/uuid:66d4041f-5b78-4006-b9fa-ae18ad9ae01c/datastream/OBJ/view