Antennas - Science topic

This paper aims to investigate and design a Yagi disc antenna with a variable number of director elements for Band 3 in fourth-generation long term evolution (4G LTE) mobile applications. The array technique was introduced by increasing the number of director elements to achieve superior results and better performance, such as higher gain and lower...

Cellular networks are becoming increasingly complex, requiring careful optimization of parameters such as antenna propagation pattern, tilt, direction, height, and transmitted reference signal power to ensure a high-quality user experience. In this paper, we propose a new method to optimize antenna direction in a cellular network using Q-learning....

In this paper, the design and analysis of dual bands antenna is carried out. The ranges of frequencies are below 6 GHz and above 24 GHz. The superformula was used to design the proposed antenna where the curve profile of the proposed antenna is obtained by adjusting the six different parameters of the super-formula. The antenna shape likes the sunf...

In this study, it is aimed to obtain two different asymmetric radiation patterns obtained from antennas in the shape of the cross-section of a parabolic reflector (fan blade type antennas) and antennas with cosecant-square radiation characteristics at two different frequencies from a single antenna. For this purpose, firstly, a fan blade type anten...

p>Antenna design has significantly advanced as a result of the widespread need for wireless communications and data substitution through wireless devices. The research article's goal is to provide a conceptual framework, difficulties, and opportunities for a source as well as a general overview of the antenna used in wireless communications applica...

The aim of the study involves the design of a novel annular seven tooth antenna and comparing its gain, return loss with a circular patch. Totally 38 samples are considered for the analysis which is obtained using the G power tool by fixing the pretrained power and the error rate as 0.811 and 0.051 respectively. The total 38 samples are grouped int...

In this research we have obtained fractional electromagnetic fields in DPS and DNG regions using standard fractional vector cross product(SFVCP). We have also calculated fractional electromagnetic fields of a travelling electromagnetic wave in DPS and DNG region with oblique incidence using SFVCP. This approach is new as the definition of SFVCP is...

One of the biggest challenges in modern communication systems is to provide a single antenna for multiple applications. Existing antenna systems are limited to some applications. Therefore, it is important to design a single reconfigurable antenna for multiple applications in current communication systems. To overcome this problem, a single antenna...

This article presents a simple planar millimeter-wave (mm-wave) multiple input multiple output (MIMO) antenna with four closely spaced radiating elements. The antenna is intended to enhance the bandwidth for 5G new radio (NR) applications and also cover the industrial Ka-band (26.5-40 GHz), Q-band (30-50 GHz), and U-band (40-60 GHz) frequency range...

A shape adjustment method for subreflectors based on minimizing the residual wavefront error of the large dual-reflector antenna is presented. This method is used to compensate for the antenna structural deformation caused by environment loading. The shape of the subreflector is adjusted using actuators fixed under the panels. The shape adjustment...

A 1 × 2 low-profile filtering antenna array is proposed, using an H-shape resonator to feed two strip dense dielectric patch (DDP) resonators. The even–odd mode of the H-shape resonator and the TMδ1 mode of the strip DDP resonator form the radiation band. Additionally, the odd–odd mode of the H-shape resonator excites the TMδ2 mode of the strip DDP...

The inverse finite element method (iFEM) based on fiber grating sensors has been demonstrated as a shape sensing method for health monitoring of large and complex engineering structures. However, the existing optimization algorithms cause the local optima and low computational efficiency for high-dimensional strain sensor layout optimization proble...

Beetles of the family Scarabaeidae, commonly known as dung or rhinoceros beetles, can be easily identified by their lamellate or clubbed antennae and stout body. Study period was lasted from January 2022 to December 2022. Beetles specimens were collected two times per month. Specimens were preserved in glass bottles containing 70% alcohol and some...

The grey wolf optimization (GWO) algorithm is a new nature-inspired meta-heuristic algorithm inspired by the social hierarchy and hunting behavior of grey wolves. In this paper, the GWO algorithm is improved to overcome previous shortcomings of being easily trapped in local optima and having a low convergence rate. The proposed enhancement of the G...

In this paper, a single-wall carbon nanotube(SWCNT) is used to design an on-body patch antenna for biotelemetry. One of the worst diseases is a lung tumor, which has the potential to spread throughout the body and cause cancer. This paper's primary goal is to use a novel material and observe variation in the S1,1 parameter to identify lung tumors....

In this paper, an efficient, coplanar waveguide (CPW)-fed printed circular ring fractal ultra-wideband (UWB) antenna is presented for biomedical applications. In UWB technology, short-range wireless communication is possible with low transceiving power, a characteristic that is particularly advantageous in the context of microwave and millimeter-wa...

The paper mainly focuses on developing a Square-shaped Microstrip Patch Antenna Design using Three Dimension Finite Difference Time Domain Methods. There have been many time steps for analyzing the electric field in the antenna design. The time step has been started from 0 ps to 1991 ps. The electric field changes from the starting point to the end...

The genus Sceloattalus Wittmer, 1966 is recorded from China for the first time. A new species, S. nigroprominens Tong & Yang, sp. nov. , is described and illustrated from Xizang Autonomous Region of China. This new species is the fourth member of Sceloattalus and can be easily distinguished from others by the yellow antennae with a small black spot...

A conformal tri-band antenna tailored for flexible devices and body-centric wireless communications operating at the key frequency bands is proposed. The antenna is printed on a thin Rogers RT 5880 substrate, merely 0.254 mm thick, with an overall geometrical dimension of 15 × 20 × 0.254 mm3. This inventive design features a truncated corner monopo...

Vibration mitigation of moving flexible structures is a key issue in many applications. Examples include antennas, solar arrays, radar reflectors, and manipulator arms, especially in the aerospace sector. These structures typically consist of interconnected slender and flexible elements moved by external actuators to reach specific configurations a...

In this work, we exploit a multi-antenna cooperative jammer to enable secure short packet communications in Internet of Things (IoT) networks. Specifically, we propose three jamming schemes to combat eavesdropping, i.e., the zero forcing beamforming (ZFB) scheme, null-space artificial noise (NAN) scheme, and transmit antenna selection (TAS) scheme....

In this article, a dual-frequency microstrip antenna capable of radiating sector beams and rectangular beams is designed. Firstly, the characteristic mode of microstrip antennas is analyzed, and the principle of half-power beam width (HPBW) enhancement of microstrip antennas is studied from the mode combination theory. Studies have shown that when...

In this letter, a compact, planar circularly polarized (CP) sub-GHz slot-based multiple-input-multiple-output (MIMO) antenna with dual sense CP along with polarization bandwidth reconfigurability is presented. The pentagonal reactively loaded slot is fed by two folded tapered feedlines to achieve CP. The antenna offers left-hand-circular polarizati...

Antennas using the active frequency selective surface (AFSS) can achieve fast beam‐scanning ability at a low cost. In this study, a switched beam antenna with a high gain and 360° coverage in the horizontal plane is proposed. Twelve columns of AFSS form a cylindrical cavity and are transmissive or reflective to the incident electromagnetic waves un...

In general, an antenna is an interface that transmits signal data and receives incoming signal data. The radio waves received through this interface help to do the necessary things for the transmitter and receiver circuit systems used there. Also a radio transmitter antenna transmits different waves generated from the current generated at its tip t...

Extreme mass-ratio inspirals (EMRIs) take place when a stellar-mass black hole (BH) merges with a supermassive BH (SMBH). The gravitational-wave emission from such an event is expected to be detectable by the future Laser Interferometer Space Antenna (LISA) and other millihertz detectors. It was recently suggested that the EMRI rate in SMBH binary...

In this paper, the switched-beam nanoantenna (NA) concept is introduced with a theoretical design of an inhomogeneous dielectric flat lens modelled with different materials to steer and enhance the radiation in a particular direction based on shifting the illuminator element. Firstly, the design of hybrid plasmonic NA is introduced and analyzed con...

A dual-band UWB coplanar waveguide monopole antenna is presented in this paper. The antenna proposed in this paper consists of an FR4 substrate, two ground planes, and a rectangular patch. The size of the antenna proposed is 24 × 25 × 1 mm 3 with a slit of length and width of 5.7 and 0.5 mm, respectively. We received two operating bands, a C-and Ku...

Background. The need to create, assemble and configure antenna-waveguide paths of multi-band reflector antennas of satellite communication systems requires the use of various methods for choosing the structure, determining and optimizing the parameters of antenna-waveguide paths. Aim. Reducing the requirements for the volume of computational costs...

We consider the deployment of a large-scale circular layout-distributed antenna system. To maximize energy efficiency, we define the optimization problem with the approximated analysis and find the number of deployed antennas as a closed-form solution. In simulation results, we verify that the analysis based on approximation is accurate and the clo...

InAlAs:Be/InGaAs superlattices grown at low temperatures were investigated in this study. To obtain the highest resistivity and mobility simultaneously, a growth temperature above 200 °C was applied. The electrical properties were conducted via Hall effect measurement and a photoresponse test. The experimental results demonstrate that the sample gr...

A modified E-shape dual bands rectangular microstrip patch antenna for wireless applications is presented in this paper. An E-slot Microstrip patch antenna with a defective ground structure method has been proposed and getting two bands at 1.9 GHz and 2.89 GHz with S11 -10dB. Defective ground structures provide a maximum gain and low insertion loss...

An ultra‐wideband dual circularly polarized (CP) slot antenna with high isolation is presented. Two L‐shaped probes are on the upper layer, both a ladder strip outside and a bent strip in the center on the bottom layer. The L‐shaped probes and the ladder strip result in four impedance resonance modes, and the bent strip moderates real and imaginary...

The Korean National Space Council recently released “Mars Exploration 2045” as part of its future strategic plan. The operations for a Mars explorer can be defined based on domestically available capabilities, such as ground operations, launch, in-space transport and deep space link. Accordingly, all of our exploration scenarios start from the Naro...

The massive use of electronic equipment has raised concerns about electromagnetic (EM) pollution, leading to increased attention to EM shielding in both civil and military applications. EM absorption materials play a crucial role in reducing the energy of microwaves projected onto their surface. In this work, we propose a novel OTA (over-the-air) a...

A novel double-layer Huygens’ unit with dual-polarized response and complete phase coverage has been proposed for highly efficient meta-lens antenna application. The designed unit is a symmetric structure in which the double-layer metallic patterns not only act as the electric dipoles but also induce the magnetic dipoles. The balance between the in...

p>The near-field samples (NFSs) of base-station antennas are obtained by a circular array of probes (CAP) in spherical array sampling systems. In order to reduce sampling time, this paper proposes a compressive spherical array sampling technique based on pseudo-skeleton tensor approximation (PSTA). Specifically, the Huygens’ principle and the metho...

p>This paper deals with a massive multiple-input multiple- output (mMIMO) full-duplex (FD) communication system. We propose new spatial domain self-interference cancellation (SIC) techniques. The main idea is to treat the self-interference (SI) signal emitted from the FD node as another spatial stream that needs to be precoded in the null space of...

In this paper, graphene based SRR loaded on a two-port antenna with high isolation and polarization diversity is used for THz applications. The size of the two-port antenna is compact and two microstrip-fed radiators are placed orthogonally to achieve the polarization diversity. The defective ground and stub are implemented to achieve impedance mat...

Penelitian ini merancang sebuah antena helix mode axial dengan frekuensi kerja yang digunakan sebesar 2,1 GHz yang terdapat pada rentang frekuensi radar S-Band, yang memiliki nilai Return loss < -10 dB dan VSWR < 1,3. Simulasi dilakukan dengan menggunakan sofware CST studio suite 2020 dengan merancang antena helix dari hasil perhitungan hingga dila...

p>This paper deals with a massive multiple-input multiple- output (mMIMO) full-duplex (FD) communication system. We propose new spatial domain self-interference cancellation (SIC) techniques. The main idea is to treat the self-interference (SI) signal emitted from the FD node as another spatial stream that needs to be precoded in the null space of...

Due to the expansion of wireless technology globally in terms of the number of users, there is a need to improve both the capacity and coverage of the wireless network. Such need for more capacity and coverage has a very serious cost implication in the course of deployment and maintenance of the infrastructure and other necessary things. Bent on en...

We propose a Fabry–Perot cavity (FPC) antenna to suppress a sidelobe level (SLL) while maintaining a reasonably high gain. Generally, conventional FPC antennas (FPCAs) produce a high SLL because waves in their FPC leak considerably through lateral openings, which is a primary reason for lowering antenna gains. We propose two design approaches to so...

The construction of the four-port MIMO antenna in the form of a sickle is provided in the article. Initially, the single port element is designed and optimized. Next, a structure with two ports is created, and lastly, a design with four ports is completed. This process is repeated until the design is optimized. Three types of parametric analysis ar...

A novel 2‐D beam steering technology using a Fabry–Pérot antenna with a liquid‐based reconfigurable metasurface is presented. The antenna employs a reconfigurable partially reflecting surface to regulate phase distribution and adopts a microstrip antenna as feed to realise 2‐D beam steering. The antenna beam can be tilted in four different directio...

This paper investigates and studies the Cell Free massive Multiple Input Multiple Output ( MIMO ) in which Access pints are aided by the optimized multiple antenna system. The proposed cell-free network has the ability to address many of the interference problems that currently affect cellular networks. More importantly in such networks a major iss...

p>The antennas and metasurfaces designed for biomedical applications operate primarily in the far-field rather than the near-field. Working in the near-field is considerably more intricate in both design and theory. Furthermore, the proposed methodologies are unsuitable for seamless integration with a radar system that seeks to offer an efficient a...

As the demand for large loads such as oversized cameras, antennas, and robotic arms continues to increase, the assembly tasks of medium-sized and large satellites have shown explosive growth. Compared to small satellites, their assembly is more difficult, their development cycle is longer, and they occupy more resources, placing higher requirements...

En el contexto actual donde existe una aparición permanente de competidores a nivel global, nuevos escenarios sin fronteras generados por las tecnologías de la información y la comunicación (TIC), la generación permanente de grandes volúmenes de datos e información, la libre circulación del conocimiento, y otros factores, obligan a las organizacion...

A new wideband cross-dipole antenna (CDA) with a circularly polarized (CP) characteristic is proposed in this article. The antenna consists of four L-shaped patches, two modified trapezoid-microstrip lines as an impedance tuner, a pair of vacant-quarter feeding loops as a continuous-phase feeding network, and four grounded inverted L-shaped strips...

p>The antennas and metasurfaces designed for biomedical applications operate primarily in the far-field rather than the near-field. Working in the near-field is considerably more intricate in both design and theory. Furthermore, the proposed methodologies are unsuitable for seamless integration with a radar system that seeks to offer an efficient a...

A compact wideband MIMO antenna obtained by breaking up an intact rectangular patch into a 2 × 5 small patch array with connected strips is proposed for 5G mobile terminals. The diagonal small patches are connected with the metal strips respectively, so as to constitute an interleaved double branch composed of a main branch and a parasitic branch,...

This paper provides a description of what we term Flex-Capsule (a similar vendor flight development is termed Twist Capsule), discusses the reasoning behind choosing a new engineering development over maintaining heritage, and includes commentary pertaining to life cycle analysis, electrical performance, and flexible PCB lubrication. Lessons learne...

The conformal antenna is a precision device installed on the wing of an aircraft, and its components are distributed on a curved surface. Quality detection is required after assembly. In solving the path planning problem for conformal antenna surface detection, the traditional genetic algorithm faces problems such as slow convergence and easily fal...

A defected grounded hexagonal patch antenna tuned at 5.17 GHz is designed in this manuscript. This antenna has reflection coefficient of-39.41 dB at its resonant frequency. It provides a fractional bandwidth of 22.97% around 5.17 GHz and it radiates over wide frequency range of 4.66 GHz to 5.85 GHz. This antenna possesses 1.63 dBi realized gain at...

We designed a mesoscopic dielectric cuboid antenna connected to a flangeless WR-3.4 open-ended waveguide, and the antenna characteristics at 300 GHz were examined through simulations and experiments. Simulations confirmed that the flangeless design eliminated the flange-induced ripples in the radiation pattern, whose shape varied with frequency, an...

The transmit waveform with ambiguity function specifications in the range‐Doppler plane has been of great interest in traditional single antenna radar systems in recent years. This paper considers the design of waveform sets with a desired slow‐time ambiguity function for multiple‐input multiple‐output radar. Specifically, it is desirable that the...

A compact and novel ultrawideband (UWB) antenna integrated with Ku band for microwave imaging applications is reported. The reported antenna consists of a novel patch structure along with a tapered feed structure on top of FR‐4 substrate having a compact dimension of 16 × 22 mm² and novel semicircular defected ground structure (SC‐DGS) etched below...

This article presents a study on the placement of multiple nulls as well as minimization of side lobe level in the radiation pattern using a planar hexagonal antenna array structure in two different vertical planes. The desired null depth is achieved to suppress the interference signal by the position‐only control of the uniformly excited isotropic...

With the advancement of multi-GNSS systems, the field calibration of GNSS receiver antennas has been updated at Wuhan University. Benefiting from the use of a six-axis robot that can change its position and attitude precisely, multisession calibration experiments were implemented for several antennas of two types. The calibrations show a high stabi...

This paper presents the review on the design of various reconfigurable antennas and their applications in the current scenario. There are more challenges involved in the design of these antennas. This paper also describes the various methods used for reconfiguring the frequency bands. The single parameter reconfiguration and hybrid reconfiguration...

This study demonstrates the application of liquid crystals to modulate the resonance properties of Yagi-Uda metamaterial absorbers. The absorbance and reflectance peak frequencies and amplitudes were found to be adjustable by reorienting the liquid crystal, irrespective of the polarization of the incident light. Notably, the lowest resonant frequen...

The Pselaphinae fauna of Hubei Province in central China is extremely poorly documented. Here we describe two new species recently collected at a riverbank near Chongyang’s county seat. Batrisiella riparia sp. nov. is characterized by the greatly swollen metafemora of the male, and Nipponobythus varicornis sp. nov. has a darkish-colored body, and u...

This research work was aimed at investigating and determining the depth resolution of a 500Mhz GPR Antenna. The survey was conducted in an open space at the Physics Department, College of science-KNUST. The MALA GPR equipment with 500MHz shielded Antenna in the common offset-mode was used to investigate the depth at which materials were buried. Con...

In this paper, the design parameters, such as spacing and antenna length are examined in detail for the terahertz photoconductive antenna arrays operating in the terahertz frequency region, which is one of the most important band candidates for future communication systems, and a 1x4 wide-band time-domain bowtie antenna array providing 30° steering...

In this paper, the directional antenna is developed to construct the printed dual‐frequency directional antenna for a 1‐GHz/2.3‐GHz dual‐frequency sensor application. An auxiliary dipole element generating the higher resonant mode is set on a primary dipole element introducing the lower resonant mode. The feed balance is also designed to cover the...