Results 51 to 60 of about 2,907 (204)

A low‐power and area‐efficient ultrasound receiver using beamforming successive approximation register analog‐to‐digital converter with capacitive digital‐to‐analog converter combined delay cell structure for 3‐D imaging systems

open access: yesElectronics Letters, 2022
The authors present a low‐power area‐efficient subarray beamforming receiver (RX) structure for a miniaturized 3‐D ultrasound imaging system. Given that the delay‐and‐sum (DAS) and digitization functions consume most of the area and power in the receiver,
Seungah Lee, Soohyun Yun, Joonsung Bae
doaj   +1 more source

Hybrid Precoding Using Out-of-Band Spatial Information for Multi-User Multi-RF-Chain Millimeter Wave Systems

open access: yesIEEE Access, 2020
With a tremendous amount of underutilized bandwidth, millimeter wave (mmWave) communication is a promising solution to meet the increasing data-rate demands.
Zhannan Li   +3 more
doaj   +1 more source

Analog beamsteering for flexible hybrid beamforming design in mmwave communications [PDF]

open access: yes2016 European Conference on Networks and Communications (EuCNC), 2016
In this paper, we propose an analog beamsteering approach for enabling flexible hybrid beamforming design that can achieve performance close to singular value decomposition (SVD) based digital beamforming with single user case. As a starting point, assuming the use of a codebook with infinite precision, we apply transposes of antenna array response ...
Yaning Zou   +2 more
openaire   +2 more sources

Radix-2 Self-Recursive Sparse Factorizations of Delay Vandermonde Matrices for Wideband Multi-Beam Antenna Arrays

open access: yesIEEE Access, 2020
This paper presents a self-contained factorization for the Vandermonde matrices associated with true-time delay based wideband analog multi-beam beamforming using antenna arrays. The proposed factorization contains sparse and orthogonal matrices.
Sirani M. Perera   +2 more
doaj   +1 more source

Intelligent Acousto‐Electrical Metamaterials (IAM) for Sound Source Detection

open access: yesAdvanced Materials, EarlyView.
Our proposed metamaterial concept enables sound source detection using a single material, in contrast to conventional arrays that require dozens or even hundreds of transducers. We show that the coupled acoustic–vibrational–electrical responses in piezoelectric metamaterials give rise to topology‐governed charge transport, producing distinct voltage ...
Victor Couëdel   +7 more
wiley   +1 more source

Transducers Across Scales and Frequencies: A System‐Level Framework for Multiphysics Integration and Co‐Design

open access: yesAdvanced Materials Technologies, EarlyView.
Transducers convert physical signals into electrical and optical representations, yet each mechanism is bounded by intrinsic trade‐offs across bandwidth, sensitivity, speed, and energy. This review maps transduction mechanisms across physical scale and frequency, showing how heterogeneous integration and multiphysics co‐design transform isolated ...
Aolei Xu   +8 more
wiley   +1 more source

Analog Beamforming and Digital Beamforming on Receive for Range Ambiguity Suppression in Spaceborne SAR [PDF]

open access: yesInternational Journal of Antennas and Propagation, 2015
For future spaceborne synthetic aperture radar (SAR) missions, digital beamforming (DBF) on receive in elevation to form a sharp high receive beam will be adopted to improve the signal to noise ratio (SNR) level and suppress range ambiguities. However, in some special cases, range ambiguities may be received by grating lobes with the high receive beam ...
Pingping Huang, Wei Xu
openaire   +2 more sources

3D Large‐Scale Subwavelength‐Resolution Sound Sheet Tomography Based on an Active and Programmable Circular Meta‐Array

open access: yesAdvanced Science, EarlyView.
A programmable 2048‐element circular ultrasound array combined with a compact acoustic lens produces a thin “sound sheet” over a large field of view, and records echoes with wide angular diversity across the ring aperture. Coherence‐enhanced beamforming converts full‐matrix data into high‐contrast tomographic slices, delivering near‐diffraction‐limited
Qiu‐De Zhang   +11 more
wiley   +1 more source

Hybrid Analog-Digital Beamforming for Massive MIMO Systems

open access: yesCoRR, 2017
In massive MIMO systems, hybrid beamforming is an essential technique for exploiting the potential array gain without using a dedicated RF chain for each antenna. In this work, we consider the data phase in a massive MIMO communication process, where the transmitter and receiver use fewer RF chains than antennas. We examine several different fully- and
Shahar Stein Ioushua, Yonina C. Eldar
openaire   +2 more sources

User-Driven Relay Beamforming for mmWave Massive Analog-Relay MIMO

open access: yes, 2023
Sixth-generation mobile communication (6G) aims to further improve capacity and reliability by controlling the radio propagation environment. Millimeter wave (mmWave) high-frequency band communication offers large bandwidth at the cost of high ...
Yoghitha Ramamoorthi   +5 more
core   +1 more source

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