Article
Telecommunications
Shuhao Zeng, Hongliang Zhang, Boya Di, Yunhua Tan, Zhu Han, H. Vincent Poor, Lingyang Song
Summary: This letter explores a downlink multi-user RIS-assisted communication network, discussing the three types of RIS implementations and their performance under specific user distributions. Numerical results validate the analysis.
IEEE COMMUNICATIONS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Susanne Brandl, Mario Mueh, Adrian Diepolder, Ekaterina Kunakovskaya, A. Cagri Ulusoy, Christian Damm, Christian Waldschmidt
Summary: Reflectarrays and tunable surfaces are receiving increasing attention for wavefront engineering in the upper millimeter-wave range. This article evaluates two unit cell (UC) designs with integrated phase shifter and on-chip antenna experimentally at 240 GHz. The results of two different measurement methods are compared and interpreted using full-wave simulations.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Sen Liu, Qiang Chen
Summary: This article proposes a novel wideband, multifunctional space-fed planar array antenna design with independently controlled forward/backward beams by introducing a novel polarization-dependent unit cell and developing a GSM-based network model. Through system-level analysis, the design concept is verified with a prototype demonstrating the expected performance. Additionally, experimental results confirm the potential for bidirectional wireless communication applications.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Yujie Zhang, Zixiang Han, Shiwen Tang, Shanpu Shen, Chi-Yuk Chiu, Ross Murch
Summary: This article introduces a novel single-fed horizontally polarized pattern-reconfigurable antenna that is highly capable of generating various radiation patterns. The antenna is able to achieve flexible beam steering and full 3-D space scanning without the use of phase shifters. Experimental and simulation results demonstrate the antenna's performance in different radiation modes, showcasing its high pattern reconfigurability and versatility for sub-6 GHz wireless applications.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Telecommunications
Shuhao Zeng, Hongliang Zhang, Boya Di, Haichao Qin, Xin Su, Lingyang Song
Summary: Holographic Multiple Input Multiple Output (HMIMO) is an important component for future wireless networks, integrating massive antenna elements into a compact space. Reconfigurable refractive surface (RRS) acts as an energy-efficient solution for HMIMO, outperforming phased arrays in terms of power consumption.
IEEE COMMUNICATIONS LETTERS
(2022)
Article
Engineering, Aerospace
Esmaeil Kavousi Ghafi, Seyed Ali Ghorashi, Esfandiar Mehrshahi
Summary: This article introduces a novel method for reconfiguring antennas to achieve desired beam patterns through multiple steps. By turning off the least important antennas and maintaining a predefined number of antennas, the proposed method outperforms existing methods in terms of beam-pattern matching and computational complexity.
IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS
(2021)
Article
Engineering, Electrical & Electronic
Ender Ozturk, Birsen Saka
Summary: A novel multilayer unit cell structure is proposed in this study to achieve a broad phase range for reflectarray antennas using Minkowski fractal-shaped reflectors and aperture coupled phasing stubs, resulting in smaller unit cell size and interelement spacing. Simulations and experiments at 10 GHz show promising results with good agreement between simulation and measured data.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Ghanshyam Mishra, Satish Kumar Sharma
Summary: The novel Ka-band Butterfly phased array antenna features full-polarization reconfigurability, flexible radiation pattern, and wide-angle beam steering performance. By adjusting the excitation of the ports, different polarizations can be achieved, providing dynamic beamwidth and flexible radiation characteristics.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Heedong Do, Namyoon Lee, Angel Lozano
Summary: This paper establishes an upper bound on the capacity of line-of-sight multi-antenna channels and shows how uniform linear arrays (ULAs) with SNR-dependent rotation or electronically selecting among multiple ULAs with radial disposition can closely approach or achieve such capacity. The study also introduces reduced-complexity precoders and linear receivers that optimize the channels spawned by these configurable ULA architectures, achieving 96% of capacity with only three ULAs.
IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS
(2021)
Article
Engineering, Electrical & Electronic
Meini Wang, Min Tang, Le Peng Zhang, Hao Chi Zhang, Jie Xu, Tie Jun Cui, Junfa Mao
Summary: By utilizing planar periodic slow-wave structure (PSWS), the miniaturization of frequency-reconfigurable antennas is achieved with controlled dispersion features. The operating frequency can be electronically adjusted by varactors, making it suitable for ultra-compact frequency hopping communication systems.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Kevin A. Leon, Joshua Haney, Sungkyun Lim
Summary: This paper proposes a size-reduced circularly polarized log-periodic dipole array (CPLPDA) with curved T-shaped top loading for element size reduction, achieving a 50% reduction in element length compared to full-sized CPLPDA elements. The antenna, with six elements, demonstrates an 87.0% impedance bandwidth and a 50.0% axial ratio bandwidth in measurements. The common bandwidth between the -10 dB impedance bandwidth and 3 dB axial ratio bandwidth is 50.0%. The peak realized gain in the direction of the shortest element is 6.60 dBi over the common bandwidth.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Yunjie Guan, Yong-Chang Jiao, Yang-Dong Yan, Yunxia Feng, Zibin Weng, Jifeng Tian
Summary: This letter introduces a wideband and compact Fabry-Perot resonator antenna (FPRA) with two layers of partially reflective surfaces (PRSs), utilizing regular hexagonal units for the first time. The compact arrangement of regular hexagonal units and the addition of tripod branches significantly reduce the size of the antenna. The periodic arrangement of regular hexagonal units along three directions allows for a positive phase gradient, enabling wideband operation in the range of 9.1-13.5 GHz.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2021)
Article
Computer Science, Information Systems
Ye-Yeong Jeong, Seong-Hyeop Ahn, Jinhwan Koh, Wang-Sang Lee
Summary: This paper presents a printed dipole antenna array with a reconfigurable feeding network for wide elevation angle of U2X communications. The proposed array utilizes a reconfigurable feeding network consisting of switches, power dividers, and couplers to achieve high gain and wide beam coverage. The measured results show that the proposed array has large impedance bandwidth, peak gain, and half-power beamwidths at F=0 degrees and F=90 degrees.
Article
Engineering, Electrical & Electronic
Elham Baladi, Min Yin Xu, Nicolas Faria, Jeff Nicholls, Sean Victor Hum
Summary: This work presents the design and experimental validation of a dual-band fully reconfigurable circularly polarized reflectarray antenna for satellite communication applications in the Ku-band. The antenna provides simultaneous and independent beam control and achieves a phase range of over 300 degrees in both frequency bands. The fully tunable performance of the antenna is validated through experiments.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Peter Callaghan, Pavlos Giannakou, Simon G. King, Maxim Shkunov, Paul R. Young
Summary: A simple, low-cost, linearly polarized reconfigurable reflectarray surface is introduced in this study, allowing for beam steering over a wide range of angles in one plane. The technology has great potential for widespread deployment in wireless systems and can aid system designers with simple equations for design and manufacturing using screen-printing techniques.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
T. E. Esparza-Aguilar, J. Rodriguez-Cuevas, A. E. Martynyuk, J. I. Martinez-Lopez
ELECTRONICS LETTERS
(2020)
Article
Engineering, Electrical & Electronic
Rosalba Martinez-Lopez, Jorge Rodriguez-Cuevas, Alexander E. Martynyuk, Jose Martinez-Lopez
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2020)
Article
Engineering, Electrical & Electronic
Chenyu Liang, Jose Martinez-Lopez, Patrick Roblin, Yunsik Hahn, Dominic Mikrut, Vanessa Chen
Summary: A new type of wideband dual-input hybrid Doherty outphasing power amplifier (HDO-PA) has been developed, with load-modulation scheme continuously converting from the previous HDO-PA mode to the conventional Doherty PA mode as the frequency increases. Experimental results show variations in efficiency and power performance of the amplifier at different frequencies.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2021)
Article
Engineering, Electrical & Electronic
Ruwaybih Alsulami, Patrick Roblin, Jose Martinez-Lopez, Yunsik Hahn, Chenyu Liang, Zoya Popovic, Vanessa Chen
Summary: This article introduces the architecture and design methodology for a new type of dual-band Doherty power amplifier, called the 3-Way DB-DPA, which improves efficiency in dual-band operation by utilizing an auxiliary amplifier to handle both bands.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2021)
Article
Computer Science, Information Systems
Hsiu-Chen Chang, Patrick Roblin, Yunsik Hahn, Jose I. Martinez-Lopez, Chenyu Liang
Summary: This study discusses the strategy for selecting the second-harmonic input impedance, the necessity of active injection, and the methodology for designing an embedded broadband diplexer. The importance of the phase of the injected second-harmonic signal for both CW and modulated signals is demonstrated through simulation and measurement.
Article
Engineering, Electrical & Electronic
Chenyu Liang, Patrick Roblin, Yunsik Hahn, Jose Martinez-Lopez, Hsiu-Chen Chang, Vanessa Chen
Summary: This work introduces a novel design theory for a single-input hybrid Doherty power amplifier (PA) that achieves wideband load modulation. A modified design allows for the correct load modulation and minimizes the circuit size. Experimental results show that the amplifier achieves high efficiency and low adjacent channel leakage ratio (ACLR) in the frequency range of 2.5 to 3.3 GHz.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Computer Science, Information Systems
Yunsik Hahn, Jose I. I. Martinez-Lopez, Patrick Roblin, Ruwaybih Alsulami, Zoya Popovic, Vanessa Chen
Summary: This article discusses the issue of cross-modulation products in dual-band transmitters and proposes a PA model that includes four major cross-modulation products. Experimental results show that DPD can significantly improve the performance of ACPR and EVM when using the proposed model for linearization.
Article
Computer Science, Information Systems
Henry Fabian-Gongora, Alexander E. Martynyuk, Jorge Rodriguez-Cuevas, Lourdes Martinez-Lopez, Rosalba Martinez-Lopez, Jose I. Martinez-Lopez
Summary: This paper presents a tunable triband frequency selective surface unit cell based on varactor-loaded split ring slots, achieving close band response and independent band tuning by adjusting the capacitance. The simulated and measured results demonstrate successful frequency tuning and close band response with insertion loss improvements when using biasing diodes.
Article
Computer Science, Information Systems
Lourdes Martinez-Lopez, Rosalba Martinez-Lopez, Alexander E. Martynyuk, Jorge Rodriguez-Cuevas, Henry Fabian-Gongora, Jose I. Martinez-Lopez
Summary: This paper introduces a polarization insensitive frequency selective surface (FSS) based on concentric ring slots with five closely spaced passbands, achieved through modified geometry to enable the desired response within the first five transmission bands, effectively meeting the requirements for a multi-band FSS.
Article
Computer Science, Information Systems
Lourdes Martinez-Lopez, Rosalba Martinez-Lopez, Jorge Rodriguez-Cuevas, Alexander E. Martynyuk, Jose Martinez-Lopez
Summary: This paper presents a dual circularly-polarized multilayer reflective surface for reflectarray applications, which consists of a wideband multilayer circular polarizer and a multilayer reflective screen with independent phase shifting properties. The proposed approach successfully converts circularly-polarized waves to linearly polarized waves and then back to circularly polarized waves, allowing for independent phase shifting of the waves.
