A5101853600- Advanced Antenna and Metasurface Technologies
- Antenna Design and Analysis
- Advanced Materials and Mechanics
- Metamaterials and Metasurfaces Applications
- Advanced Sensor and Control Systems
- Luminescence Properties of Advanced Materials
- Laser-Matter Interactions and Applications
- Advanced Wireless Communication Technologies
- Advanced Data Storage Technologies
- Industrial Technology and Control Systems
- Caching and Content Delivery
- Optical properties and cooling technologies in crystalline materials
- Quantum optics and atomic interactions
- Advanced X-ray and CT Imaging
- Nonlinear Optical Materials Studies
- Peer-to-Peer Network Technologies
- Solid State Laser Technologies
- RFID technology advancements
- Radiation Detection and Scintillator Technologies
- Laser-induced spectroscopy and plasma
- Advanced MIMO Systems Optimization
- Advanced Computational Techniques and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Geochemistry and Elemental Analysis
- Piezoelectric Actuators and Control
Shanghai University
2024
Pingxiang University
2022
Center for Information Technology
2020
Tsinghua University
2015-2019
Institute of Microelectronics
2018
One of the key enablers future wireless communications is constituted by massive multiple-input multiple-output (MIMO) systems, which can improve spectral efficiency orders magnitude. In existing MIMO however, conventional phased arrays are used for beamforming. This method results in excessive power consumption and high hardware costs. Recently, reconfigurable intelligent surface (RIS) has been considered as one revolutionary technologies to enable energy-efficient smart communications, a...
Design of a circularly polarized reconfigurable reflectarray antenna (RRA) at X band is presented. The RRA element employs concentric dual split rings, and can be mechanically rotated to obtain continuous 360° phase coverage with negligible loss. A prototype 15 × manually elements first computed, simulated, measured. Full-wave simulations show that the gain beam focused in (8 = 20°, φ 0°) direction 25.8 dB 1-dB bandwidth over 28.6%. measured results achieves maximum 25.6 dB, corresponding an...
Design of a C-band reconfigurable reflectarray antenna (RRA) is presented. The RRA element consists fixed upper patch and tunable slotted patch. By mechanically controlling the height patch, has phase shift range 324° with small loss. A prototype 408 elements designed fabricated. measurements show that gain 20° scanned beam 25.7 dB aperture efficiency 48.6%. large-angle beam-scanning capability also verified within ±60° angular range, well-defined beams are obtained maximum scan loss 3.4 dB.
We study two-photon scattering by a two-level giant atom in waveguide. first the case that is coupled to waveguide via two coupling points, and obtain Bethe ansatz eigenstates eigenvalues Hilbert space of two-excitation. Then we derive bound states subtracting corresponding solutions from entire two-excitation space, construct matrix (S-matrix) using states. further properties output states, which include both for arbitrarily incident concrete example. find oscillation period decay rates...
As a branch of sphere decoding, the K-best method has played an important role in detection large-scale multiple-input-multiple-output (MIMO) systems. However, as numbers users and antennas grow, preprocessing complexity increases significantly, which is one major issues with method. To address this problem, paper proposes algorithm combining Cholesky sorted QR decomposition partial iterative lattice reduction (CHOSLAR) for 64-quadrature amplitude modulation (QAM) 16 $\times$ MIMO system....
A new technique for designing low-profile filter-antennas with wideband harmonic suppression capability is introduced. filter-antenna element in a periodic infinite array consists of radiating patch and an asymmetric frequency selective surface inductive wire grid cascaded capacitive metallic strips. Based on this topology, operating at 2.12 GHz was designed extremely small thickness approximately λ/27. desirable second-order bandpass response excellent better than 30 dB over 2.4-10.0 were...
A novel 2-bit reconfigurable reflectarray element for both linear and circular polarizations is proposed. The structure a microstrip patch backed by slot-loaded plane. Combining the current reversal mechanism tunable resonance approach, five PIN diodes are integrated on slots to control direction effective slot length, which lead phase shift. simulated results show that this has desired resolution at L band low loss of less than 0.31 dB. 1-dB obtained within wide bandwidth 24.7%.
The design of a Ku-band reconfigurable reflectarray element is presented in this paper. structure microstrip patch loaded with two asymmetric slots are employed, on which MEMS switches integrated to achieve 2-bit phase reconfigurability. Simulation results show that four well-distributed states can be electronically controlled, and the maximum amplitude loss less than 0.70 dB. proposed successfully balances performance system complexity, becoming potential candidate for high-performance...
One of the key enablers future wireless communications is constituted by massive multiple-input multiple-output (MIMO) systems, which can improve spectral efficiency orders magnitude. However, in existing MIMO conventional phased arrays are used for beamforming, result excessive power consumption and hardware cost. Recently, reconfigurable intelligent surface (RIS) has been considered as one revolutionary technologies to enable energy-efficient smart communications, a two-dimensional...
The distributed power-amplifying capability is investigated to improve the effective isotropic radiated power (EIRP) of reflectarray antennas. For experimental verification purpose, a C-band with 12 × elements designed and fabricated, where aperture-coupled patch element orthogonal H-shaped slots an integrated amplifier employed. Element simulations show that reflection coefficients are below -10.0 dB isolation better than 31.8 for various lengths microstrip line oblique incident angles at...
The design of an X-band circularly polarized reconfigurable reflectarray antenna is presented. Elements with concentric dual split rings are mechanically rotated by micromotors to achieve phase reconfigurability low cross-polarization and element loss. Simulation results show that a maximum gain 26.43 dB aperture efficiency 62.9% achieved 15×15 elements. Excellent beam scanning characteristics also validate its reconfigurability.
A novel reconfigurable reflectarray element with an internal slotted patch of tunable height is proposed. The inserted between a fixed upper and the ground plane, whose mechanically controlled by actuator to achieve phase reconfigurability. Based on Phoenix concept, initial final states proposed are almost same, except slight increase in size. Simulation results show that smooth coverage 322° low magnitude loss 0.05 dB obtained. suitable for both linear circular polarizations, due symmetric...
An active reflectarray antenna design using power amplifiers is presented in this paper. The aperture-coupled element structure with orthogonally polarized ports adopted. Stable port impedance matching for different microstrip line lengths achieved by reducing the mutual coupling between adjacent elements. Port isolation improved to over 30 dB ensure stability of amplifier. amplifying 12×12 elements at 5.8 GHz designed numerical verification. Full-wave simulation shows that passive gain 27.6...
최근 데이터베이스 보안을 위한 다양한 암호화 방법이 제안되고 있다. 이러한 방법들은 사용자의 민감한 데이터를 효과적으로 보호할 수 있지만 질의어에 대한 검색 성능이 저하된다. 본 논문에서는 단점을 보완하기 위하여 블룸필터에서의 선택적 요소 단위의 방식을 제안하였다. 그리고 다수의 질의어를 통하여 기존에 제안된 튜플 방식과 성능을 비교하였다. 결과적으로 정보에 대하여 방법을 적용하고, 이에 인덱스로서 블룸필터를 사용한 제안 방식이 방식보다 시간이 매우 빠르게 나타남을 알 There are a lot of encryption methods to secure database proposed recently. Those can protect the sensitive data users effectively, but it deteriorates search performance query. In this paper, we selective element method in order...
As a kind of sponge city water-permeable material, permeable brick has good water permeability, chemical stability, corrosion resistance and weather resistance. Therefore, the development also broadens engineering application market for its application. The discharge large amount manganese slag will cause serious environmental pollution, problem tailings accumulation is serious. There no ideal treatment method at present. In this paper, used as main raw material to prepare bricks, thereby...