Antenna Components Research Articles

Design and Optimization of Multi-petal Damping Structure for Vibration Control of Satellite Antenna Component

A preloaded multi-petal friction damping structure is proposed for deployment mechanism of large-scale flexible deployable satellite antenna. The damping structure is designed to suppress transverse vibration for promising stability and accuracy in the deployment process. In order to study the damping property of multi-petal damping structure and facilitate theoretical modelling, the model of deployment component with damping structure is simplified as double-layer cantilever beam model to study mechanical properties of friction and damping energy dissipation mechanism. The optimum parameters of damping structure are determined by numerical analysis of the simplified modal and the hysteresis curve can be obtained by finite element simulation to calculate loss factor. In the dynamic simulation, the loss factor can reach 0.2685 and the vibration amplitude can be reduced by more than 65%, which indicates the excellent effect for vibration suppression and the feasibility of the proposed structure.

Perkembangan Teknologi Antena Solar: Satu Tinjauan

Solar energy generally is the natural solution of environmental pollution due to fossil fuel burning to fulfil the electrical energy demands today. As it is the alternative of a limited source, research on solar energy caught attention of various industry and field experts due to its renewability characteristic. Communication technology industry is not an exception. The advancement in the current industry makes the integration of solar and antenna is crucial to be explored to cater issues such as limited surface area on a device, or for standalone application that required self-powered telecommunication system. It is an obligatory to analyse the features of current solar antenna as an initial step before the process of improvement and adaptability of design and application that will be done next. In this paper, a thoroughly review of advancement of the solar antenna design technology are discussed. These antennas are divided to solid type, semi-transparent type, and transparent type according to its antenna components’ transparency. For each category, the features that reviewed are the antenna configuration, material used in the design, type of solar cell used, operating frequency of the antenna, performance of the solar antenna and the integration process done.

MmWave 5G NR Cellular Handset Prototype Featuring Optically Invisible Beamforming Antenna-on-Display

The reduced link margins caused by undesired blockage such as the user's hand and inherent limitations of beamsteering angles for planar antenna components constitute one of the most critical challenges for future mmWave mobile devices. This underscores the need for a new beamforming antenna strategy, which can enhance the foreside coverage with minimum compromise. This article provides a detailed overview of an mmWave beamforming antenna concept denoted as an optically invisible antenna-on-display (AoD), which can enhance the CDF, especially in the foreside direction of mobile devices such as cellular handsets. In contrast to existing antenna component strategies, the AoD is integrated within the view area of high-resolution OLED or LCD display panels of cellular handsets while remaining unnoticeable to the human eye through the use of nano-scale patterns. This allows the realization of highly precise beamforming in the foreside direction for large-screen mobile devices. The fundamental phased-array AoD strategy is introduced and compared with existing mmWave 5G beamforming antenna strategies for mmWave 5G NR cellular handsets. The operating mechanism of the mmWave 5G phased-array AoD component and its integration with existing wireless component architectures and a 537 ppi density OLED panel are considered. This concept is further refined by integrating a series of fabricated 28 GHz phased-array AoD components within a real-life mmWave 5G NR Android-based cellular handset prototype reported in the literature for the first time. The foreside beamforming characteristics at 28 GHz are experimentally studied followed by investigation of OTA measured EVMs using QPSK, 16- and 64-QAM mmWave 5G NR waveform signals in accordance with the 3GPP requirement.

Vibration control of deployable truss antenna reflector-scanning mechanism

Scanning mechanism and truss reflector are important components of antenna. Aiming at the mechanical system and control system composed of scanning mechanism and truss antenna, the co-simulation technology of hybrid stepping motor and flexible dynamic mechanism is proposed. Through the simulation results of the current and position changes of the antenna system, the various physical characteristics of the system during the co-simulation are studied, and the vibration characteristics of the overall antenna system are analyzed, which verifies the cooperative ability of the antenna mechanism system and the control system.

A Novel RFI Mitigation Method Using Source Rotation

This article proposes a novel radio frequency interference (RFI) mitigation method and applies it to a real consumer electronic device. Through near-field scanning, an equivalent dipole moment of the noise source containing the CPU and DDR memory chip is reconstructed. The near-field components of the victim Wi-Fi antenna are measured to obtain the transfer function. By determining the relationship between the dipole moment and the antenna near field, the noise source is rotated by a certain angle to reduce RFI. Rotating the source to reduce RFI is implemented in such a way that it does not compromise the signal integrity, and it does not require an additional shield can. New boards with the suggested changes are fabricated and the measured results show the RFI reduction up to 8 dB compared with the original board.

ШИРОКОСМУГОВІ АНТЕНИ НА ОСНОВІ КІЛЬЦЕВОЇ ГЕОМЕТРІЇ

В роботі розглянуто варіанти моделей квазіфрактальних кільцевих структур. Для їх синтезу запропонований векторний опис фрактальної трансформації окремих сегментів початкової геометричної форми. Поєднання декомпозиції геометричної форми та багатовимірного фрактального підходу дозволяє спростити синтез фрактальних 3D-структур та/або використовувати кілька видів фракталів, у тому числі, з різною кількістю ітерацій. Такий підхід дозволяє досягти широкосмуговості та багатодіапазонності антенних систем. При цьому досліджено вплив рівня сегментації та варіантів схеми живлення на просторово-частотні характеристики антени. Через складність опису взаємодії антен неевклідової геометрії з радіохвилями для їх синтезу та аналізу обрано методи чисельного моделювання. Для аналізу просторово-частотних характеристик проектованих антенних рішень використані такі показники, як зворотні втрати, діаграма спрямованості та коефіцієнт стоячої хвилі. Отримані оцінки відносної смуги пропускання δf = 0,9 свідчать про перспективність запропонованого підходу для реалізації антенних систем з високим рівнем широкосмуговості

A Building Block Assembly Dualband Dual-Polarized Antenna With Dual Wide Beamwidths for 5G Microcell Applications

A dualband dual-polarized antenna element with dual wide beamwidths for 5G microcell applications is initially proposed and investigated in this paper. To achieve very low manufacturing cost, an unprecedented method is applied to the antenna element, in which the antenna components are printed separately on F-4B substrates, follow by assembling them to form the antenna element (similar to building block assembly). To further achieve high gain, an 1 × 4 antenna array is also designed. Measured results show that the half power beamwidths (HPBWs) in H- and E-planes are 112±1° and 105±3° in the lower frequency band of 3.22-3.88 GHz, respectively, and 99±3° and 106±4° in the upper frequency band of 4.52-5.02 GHz, respectively. In addition, high front-to-back ratio (FBR) of approximately 19 dB and high isolation of 33.6 dB can also be achieved.

Recent techniques for enhancement of isolation in MIMO antenna system: a review

Nowadays the utilisation of wireless communication technologies is becoming more popular and there is a need of such ever evolving technologies. But these technologies have to provide minimum bit error rate, less fading effect, and good quality of service in order to qualify as the competent systems. Such requirements can be fulfilled with the use of multiple-input multiple-output (MIMO) antenna technology. In the MIMO antenna system, multiple antennas are used at the base station and also at the mobile terminals for the exchange of the information. For better results with the MIMO antenna system, the mutual coupling between the antenna components should be as low as possible. Due to the high mutual coupling in the antenna system, the characteristic performance of the antenna gets degraded. In this review, some recent isolation enhancement methods are discussed qualitatively. These methods have different design structures and are used in different wireless applications.

Recent techniques for enhancement of isolation in MIMO antenna system: a review

Nowadays the utilisation of wireless communication technologies is becoming more popular and there is a need of such ever evolving technologies. But these technologies have to provide minimum bit error rate, less fading effect, and good quality of service in order to qualify as the competent systems. Such requirements can be fulfilled with the use of multiple-input multiple-output (MIMO) antenna technology. In the MIMO antenna system, multiple antennas are used at the base station and also at the mobile terminals for the exchange of the information. For better results with the MIMO antenna system, the mutual coupling between the antenna components should be as low as possible. Due to the high mutual coupling in the antenna system, the characteristic performance of the antenna gets degraded. In this review, some recent isolation enhancement methods are discussed qualitatively. These methods have different design structures and are used in different wireless applications.

Design of Multiband Antenna Systems for Wireless Devices Using Antenna Boosters [Application Notes

Antennas play a significant role in the current everythingconnected era. From smartphones, to smart meters, to Internet of Things (IoT) devices, every wireless device needs at least one antenna to transmit and receive information. In response, the wireless industry is moving fast to launch new devices into this growing market. This is pushing RF/microwave and wireless engineers to design RF chains in a smart way using off-the-shelf components, such as filters, amplifiers, diplexers, and front-end modules. At the end of this RF chain, an antenna is needed to efficiently transmit/receive electromagnetic waves. Accordingly, an off-the-shelf antenna component would be an attractive option for simplifying the entire design processâ not only the antenna-design phase but also the device-manufacturing process, reducing costs and creating compatibility with pick-and-place machines for mass production.

Sequential energy transfer driven by monoexponential dynamics in a biohybrid light-harvesting complex 2 (LH2).

Enhancing the light-harvesting potential of antenna components in a system of solar energy conversion is an important topic in the field of artificial photosynthesis. We constructed a biohybrid light-harvesting complex 2 (LH2) engineered from Rhodobacter sphaeroides IL106 strain. An artificial fluorophore Alexa Fluor 647 maleimide (A647) was attached to the LH2 bearing cysteine residue at the N-terminal region (LH2-NC) near B800 bacteriochlorophyll a (BChl) assembly. The A647-attached LH2-NC conjugate (LH2-NC-A647) preserved the integrity of the intrinsic chromophores, B800- and B850-BChls, and carotenoids. Femtosecond transient absorption spectroscopy revealed that the sequential energy transfer A647 → B800 → B850 occurs at time scale of 9-10ps with monoexponential dynamics in micellar and lipid bilayer systems. A B800-removed conjugate (LH2-NC[B800(-)]-A647) exhibited a significant decrease in energy transfer efficiency in the micellar system; however, surprisingly, direct energy transfer from A647 to B850 was observed at a rate comparable to that for LH2-NC-A647. This result implies that the energy transfer pathway is modified after B800 removal. The results obtained suggested that a LH2 complex is a potential platform for construction of biohybrid light-harvesting materials with simple energy transfer dynamics through the site-selective attachment of the external antennae and the modifiable energy-funnelling pathway.

Numerical model of the radio-frequency magnetic presheath including wall impurities

Here, we present a numerical fluid plasma model able to capture the enhanced sputtering yield from the Faraday Screen and the Plasma-Facing Components of an Ion Cyclotron Resonance Heating antenna in a fusion machine. The model is a one-dimensional phase-resolved representation of a rectified radio frequency sheath in a magnetic field at an angle with respect to the material surface; the momentum transport of both ions and impurities is computed in the model. The sputtering behavior of the impurities coming off from the wall is obtained from the plasma-material interaction code Fractal-Tridyn. This study analyzes a range of magnetic angles and wave frequencies to parametrically investigate their effect on the energy-angle distributions of the impacting ions and sputtered impurities. Finally, an estimate of the impurity fluxes and of the gross-erosion rate is provided and compared with experimental data available in the literature.

Fast multi-objective design optimization of microwave and antenna structures using data-driven surrogates and domain segmentation

Purpose The purpose of this paper is to investigate the strategies and algorithms for expedited design optimization of microwave and antenna structures in multi-objective setup. Design/methodology/approach Formulation of the multi-objective design problem-oriented toward execution of the population-based metaheuristic algorithm within the segmented search space is investigated. Described algorithmic framework exploits variable fidelity modeling, physics- and approximation-based representation of the structure and model correction techniques. The considered approach is suitable for handling various problems pertinent to the design of microwave and antenna structures. Numerical case studies are provided demonstrating the feasibility of the segmentation-based framework for the design of real-world structures in setups with two and three objectives. Findings Formulation of appropriate design problem enables identification of the search space region containing Pareto front, which can be further divided into a set of compartments characterized by small combined volume. Approximation model of each segment can be constructed using a small number of training samples and then optimized, at a negligible computational cost, using population-based metaheuristics. Introduction of segmentation mechanism to multi-objective design framework is important to facilitate low-cost optimization of many-parameter structures represented by numerically expensive computational models. Further reduction of the design cost can be achieved by enforcing equal-volumes of the search space segments. Research limitations/implications The study summarizes recent advances in low-cost multi-objective design of microwave and antenna structures. The investigated techniques exceed capabilities of conventional design approaches involving direct evaluation of physics-based models for determination of trade-offs between the design objectives, particularly in terms of reliability and reduction of the computational cost. Studies on the scalability of segmentation mechanism indicate that computational benefits of the approach decrease with the number of search space segments. Originality/value The proposed design framework proved useful for the rapid multi-objective design of microwave and antenna structures characterized by complex and multi-parameter topologies, which is extremely challenging when using conventional methods driven by population-based metaheuristics algorithms. To the authors knowledge, this is the first work that summarizes segmentation-based approaches to multi-objective optimization of microwave and antenna components.

Microstrip H-Shape Patch Antenna’s Analysis and Layout

Microstrip Patch Antenna gives low contour and size, so it is utilized in specialized gadgets. It is engraved on a dielectric substrate, supported by a metal board, and directly sustained from a 50Ω coaxial link. By utilizing HFSS software design, it will be replicated. The complex impact of incorporating various methods and by presenting a novel H-shape patch provides truncated contour, extensive bandwidth and returns loss, intense gain and minimized antenna components. This sort of miniature antenna has application in cell phone for Wi-Max, Bluetooth, C-band, S-band and furthermore for different remote applications. The parameters of antenna, for example, bandwidth, return loss, VSWR, directivity and gain are examined and compared with the square patch microstrip antenna. Outcome demonstrates that the antenna has accomplished a good match of impedance, bandwidth, return loss, VSWR, Gain and Directivity.

Precisely manipulated origami for consecutive frequency reconfigurable antennas

Shape and function reconfigurable materials and structures are widely explored for their unique merits. Since wireless communication devices are critical in cutting-edge communication systems, multi-function antennas with reconfigurable capability are highly pursued to meet the requirements of operating under different situations. To address critical problems in the currently explored reconfigurable origami antenna, including antenna durability, performance and structure stability, inaccurate manipulation, insufficient tunable bandwidths, here a novel type of frequency reconfigurable origami antenna is developed coupled with a precisely manipulatable mechanism, followed by manipulation with shape memory alloy springs. By integrating the dipole antenna components, the as-manufactured origami antennas are expected to present continuous frequency reconfiguration capability in the frequency range of 0.95–1.6 GHz, implying a relative broadened tunable operating frequency of 75%. According to the simulated and experimental results, combination of origami antenna design, precise manipulation technology and multi-material 3D printing collectively promises a simple and rapid strategy for achieving advanced continuous frequency reconfigurable antennas, which hold more durable and stable ability in both antenna structures and operating performance.

Progress on an ion cyclotron range of frequency system for DEMO

An Ion Cyclotron Range of Frequency (ICRF) system can provide power for a number of tasks, experimentally verified on present machines: heating and current drive, first wall conditioning, plasma startup, removing central impurities, controlling sawteeth and current ramp down assist. The system has a high plug-to-power efficiency and most of the components external to the machine are sturdy, with industrial steady state capability.Traditional ICRF antenna systems are often characterized by a high operating voltage and high power density. Low power density and low voltage however provides a bonus in terms of reliability. Therefore, travelling wave type antennas have been proposed (Ragona and Messiaen, 2016). They can be integrated in the blanket and use only a limited number of feeders.The effect on the tritium breeding ratio of such an antenna incorporated in the blanket, including the feeders, is small. The k// spectrum is peaked and the dominant k// value can be optimized for coupling and bulk absorption, while avoiding the generation of coaxial modes in the edge. The coupling can be further enhanced with gas puffing near the antenna. Assuming the ITER-2010-low density profile, 50 MW can be coupled with a voltage on the antenna components of about 15 kV.

Massive MIMO Systems With Low-Resolution ADCs: Baseband Energy Consumption vs. Symbol Detection Performance

In massive multiple-input multiple-output (MIMO) systems using a large number of antennas, it would be difficult to connect high-resolution analog-to-digital converters (ADCs) to each antenna component due to high cost and energy consumption problems. To resolve these issues, there has been much work on implementing symbol detectors and channel estimators using low-resolution ADCs for massive MIMO systems. Although it is intuitively true that using low-resolution ADCs makes it possible to save a large amount of energy consumption in massive MIMO systems, the relationship between energy consumption using low-resolution ADCs and detection performance has not been properly analyzed yet. In this paper, the tradeoff between different detectors and total baseband energy consumption including flexible ADCs is thoroughly analyzed taking the optimal fixed-point operations performed during the detection processes into account. In order to minimize the energy consumption for the given channel condition, the proposed scheme selects the best mode among various processing options while supporting the target frame error rate. The numerous case studies reveal that the proposed work remarkably saves the energy consumption of the massive MIMO processing compared with the existing schemes.

A 400-GHz High-Gain Quartz-Based Single Layered Folded Reflectarray Antenna for Terahertz Applications

Compact high-gain antennas are highly desired in the high-speed terahertz (THz) wireless system, especially for the space limited application, such as the high-speed inter link inside the high density wireless communication base station. To this end, a 400-GHz folded reflectarray (FRA) antenna with high gain, high aperture efficiency, and compact profile is proposed in this paper. It is composed of a feed source, a single-layered reflectarray using a lithography process on quartz, and a wire-grid polarizer implemented by the printed-circuit-board technology. A 3-D printed fixture is used to assemble all parts together. In order to design accurately the proposed antenna, the THz electromagnetic properties of the supporting dielectric materials are extracted by using a THz time-domain spectrometer system. Then, a single-layered phasing element, made up of a pair of orthogonally I-shaped structures with an open square ring, is proposed and designed based on the extracted material characteristics. Both phase compensation and polarization conversion can be realized by the proposed unit cell. A reflectarray is designed by using the proposed phasing element with the conventional array synthesizing theory, and a THz grid polarizer is designed with strips on a 0.127 mm Taconic TLY-5 substrate. The THz grid is placed in front of the THz feed and the reflectarray, which is fully reflective to the feed and transparent to the reflectarray. All components of the FRA antenna have been fabricated and assembled. Experiments show that the FRA prototype has a peak gain of 33.66 dBi at 400 GHz with an aperture efficiency of 33.65%, and a 3-dB gain bandwidth of 16% (357–421 GHz).

A Broadband Circularly Polarized Wide-Slot Antenna With a Miniaturized Footprint

This letter presents a novel and simple feeding technique for exciting orthogonal components in a wide-slot antenna. In this technique, a rectangular bracket-shape parasitic strip is placed at the open end of the straight microstrip line to excite the fundamental horizontal and vertical components of the circular polarization (CP). The proposed technique—when employed in conjunction with the asymmetrical geometry of coplanar waveguide and a protruded stub from the ground plane—permits for maintaining axial ratio (AR) below 3 dB within a wide range in the C-band as well as a compact footprint of the antenna. All geometry parameters of the antenna are adjusted through rigorous EM-driven optimization to obtain the best performance in terms of footprint, impedance matching, and AR bandwidth (ARBW). The size of the proposed antenna is only 27 mm × 28.8 mm. The structure features a 62% impedance bandwidth (3.6–6.85 GHz) and ARBW of approximately 49% (3.6–5.93 GHz) with the average realized gain of 3.3 dB within the CP operating band. Numerical results are validated experimentally. A close agreement between simulation and measurement results has been observed.

Wireless Power Supply System for Flexible Space Antenna Actuators

The method of power supply via a laser channel in the cosmic space is discussed. Structure of the wireless power supply system for flexible antenna actuators is proposed and requirements to the said antenna components are stated. An energy storage unit based on lithium-ion polymer battery and supercapacitor is described in detail. Results of experimental studies for the system components are presented.