Radio Antenna Research Articles

Antenna, laboratory, archive: sound explorations at Radio Utopia

As part of the French pavilion at the XVIII Venice Architecture Biennale 2023, muoto architects with Georgi Stanishev designed the Ball Theater, associating the idea of sound creation with the architectural project from the outset. Radio Utopia occupied the Ball Theater for five days in August as part of the Pavilion's vision of architecture as a receptacle for life. Designed as a sound laboratory and radio antenna, Radio Utopia provided a platform for receiving and broadcasting discussions, testimonies, sounds and installations. The medium of the radio made it possible to question the socio-cultural conditions of an event such as the Biennale, of a restricted circle of visitors. Radio broadcasting serves as both a parable and a tangible means of connecting with distant places and potential differences using sound recording. It also offers the possibility of extending an event beyond its physical location and ephemeral temporality. Radio Utopia has left an audio trace in a corner of the Web. From the experimental perspective in the tradition of soundscape studies, this paper will look at three main aspects of the project: 1) a pavilion as a radio antenna, 2) a space of creation, a sound laboratory, and 3) a sound archiving platform.

Discovery of Limb Brightening in the Parsec-scale Jet of NGC 315 through Global Very Long Baseline Interferometry Observations and Its Implications for Jet Models

We report the first observation of the nearby giant radio galaxy NGC 315 using a global very long baseline interferometry (VLBI) array consisting of 22 radio antennas located across five continents, including high-sensitivity stations, at 22 GHz. Utilizing the extensive u v-coverage provided by the array, coupled with the application of a recently developed superresolution imaging technique based on the regularized maximum-likelihood method, we were able to transversely resolve the NGC 315 jet at parsec scales for the first time. Previously known for its central ridge-brightened morphology at similar scales in former VLBI studies, the jet now clearly exhibits a limb-brightened structure. This finding suggests an inherent limb brightening that was not observable before due to limited angular resolution. Considering that the jet is viewed at an angle of ∼50°, the observed limb brightening is challenging to reconcile with the magnetohydrodynamic models and simulations, which predict that the Doppler-boosted jet edges should dominate over the nonboosted central layer. The conventional jet model that proposes a fast spine and a slow sheath with uniform transverse emissivity may pertain to our observations. However, in this model, the relativistic spine would need to travel at speeds of Γ ≳ 6.0–12.9 along the deprojected jet distance of (2.3–10.8) × 103 gravitational radii from the black hole. We propose an alternative scenario that suggests higher emissivity at the jet boundary layer, resulting from more efficient particle acceleration or mass loading onto the jet edges, and consider prospects for future observations with even higher angular resolution.

Investigations on Penta Band High Isolation MIMO Antenna for 5G NR Bands and HIPERLAN Applications Using TCMA

The present article proposes a penta band Multiple Input Multiple Output (MIMO) antenna for 5G New Radio (NR) bands and HIPERLAN applications using Characteristic Mode Analysis (CMA). The design is obtained and optimised in step-by-step procedure using novel CMA approach and by perturbing the conventional rectangular structure with slots on the patch (left and right sides) and the ground plane (wide slot + narrow slots) for enhancing the isolation at multi bands. The MIMO configuration has a total dimension of 0.58 l0 × 0.35 l0 × 0.01 l0 mm3 with an optimum element separation of 0.05 l0 (l0 is the lowest frequency operating wavelength). Multiband resonance is produced at 2.2, 4.2, 7.2, 16, 17.5 GHz. The radiating elements can excite various characteristic modes that support wider bandwidth. The -10 dB impedance bandwidth at working region are 0.2, 0.2, 0.38, 3.6, 2 GHz respectively. The suggested design yields a gain of 2.1, 5.7, 3.5, 3.5, 5.2 dBi and consistent radiation patterns at the working frequencies. The analysis of the diversity performance considers the Diversity Gain (DG) and Envelope Correlation Coefficient (ECC), whose values are near 9.9 dB and 0, respectively. Additionally, the assessed parameters are the CCL and TARC. The structure prototype has been developed, and the observed findings are highly coherent with the simulated results, making it appropriate for use in 5G NR bands, HIPERLAN, and IoT applications.

Convolutional Neural Network Processing of Radio Emission for Nuclear Composition Classification of Ultra-High-Energy Cosmic Rays

Ultra-high-energy cosmic rays (UHECRs) are extremely rare energetic particles of ordinary matter in the Universe, traveling astronomical distances before reaching the Earth’s atmosphere. When primary cosmic rays interact with atmospheric nuclei, cascading extensive air showers (EASs) of secondary elementary particles are developed. Radio detectors have proven to be a reliable method for reconstructing the properties of EASs, such as the shower’s axis, its energy, and its maximum (Xmax). This aids in understanding fundamental astrophysical phenomena, like active galactic nuclei and gamma-ray bursts. Concurrently, data science has become indispensable in UHECR research. By applying statistical, computational, and deep learning methods to both real-world and simulated radio data, researchers can extract insights and make predictions. We introduce a convolutional neural network (CNN) architecture designed to classify simulated air shower events as either being generated by protons or by iron nuclei. The classification achieved a stable test error of 10%, with Accuracy and F1 scores of 0.9 and an MCC of 0.8. These metrics indicate strong prediction capability for UHECR’s nuclear composition, based on data that can be gathered by detectors at the world’s largest cosmic rays experiment on Earth, the Pierre Auger Observatory, which includes radio antennas, water Cherenkov detectors, and fluorescence telescopes.

Design and research of high-frequency electromagnetic wave detection antenna for discharge of transmission lines

Abstract Overhead lines have a wide range of applications in power systems. When early insulation faults occur in the long-term operation of overhead lines, corona discharge may occur. Timely detection of corona discharge can guide maintenance personnel to discover and eliminate faults in a timely manner. The height and distribution of overhead lines are relatively high, and close-range detection cannot quickly locate the discharge area. Using radio frequency antennas to measure the electromagnetic wave signals generated by corona discharge can achieve long-distance positioning detection of corona discharge. This article uses a log-periodic antenna as the detection antenna and simulates the antenna structure to prove that its directionality, gain, and measurement frequency band meet the design requirements. Finally, the discharge detection performance of the antenna is verified through experiments.

Pareto optimization of the broadband radio direction finder antenna system for small-sized mobile platforms

Pareto optimization of the broadband radio direction finder antenna system for small-sized mobile platforms

A review on microstrip patch antenna for wireless communication systems at 3.5 GHz

This article presents a review of several microstrip patch antennas for 3.5 GHz wireless applications. Different substrate materials, FR-4 (loss), FR-4 Epoxy, Rogers RT/droid 5880, TLC-30, and Rogers RT/droid 5880 LZ, are used. In recent years, wireless antenna applications have increased, including biomedical appliances, internet of things (IoT) terminals, edge devices, radars, mobile phones, and many more. In this work, several articles were reviewed and investigated, and several microstrip patch antennas with a resonance frequency of 3.5 GHz were designed using different substrate materials and shapes. This article also discussed the geometric shapes of antennas, antenna properties, sizes of substrate materials, loss tangent, thickness, return loss, bandwidth, voltage standing wave ratio (VSWR), gain, efficiency, and directivity. Several software is used for design and simulation, including computer simulation technology (CST), high-frequency simulation frequency (HFSS), and advanced design system (ADS), FEKO, and MATLAB. The main goal of this paper is to talk about different wireless application papers that work in the S-band at a frequency of 3.5 GHz and have been published in various international journals and conferences.

Wireless antenna sensor with CuO@Cu-vertical graphene and cysteine-PDMS composite for ethanol gas detection

BackgroundEthanol gas sensors are widely used in driving safety, security, and clinical respiratory monitoring applications. However, most ethanol sensors are large and exhibit poor stability owing to their integrated controller and high-temperature operation. Moreover, the development of wireless controller-free room-temperature ethanol sensors with long-term reliability is challenging. ResultsIn this study, a wireless room-temperature ethanol gas antenna sensor was developed by combining a Cu radiation electrode with vertical graphene (VG) embedded with CuO@Cu nanoparticles and a polydimethylsiloxane (PDMS) dielectric substrate filled with cysteine (Cys). In the patch-antenna sensor, changes in the ethanol gas concentration resulted in frequency shift differences in the generation and transmission processes of the synchronized sensing signal. The VG-Cu/Cys-PDMS ethanol gas sensor had a detection range of 50–2100 ppm and a low limit of detection (LOD) of 0.112 ppm, with a response/recovery time of only 20/21 s for 1200 ppm ethanol, thus demonstrating superior long-term stability and satisfactory humidity tolerance. Therefore, the synergistic sensitization mechanism between the VG sensing/radiation layer and Cys-PDMS substrate was investigated. SignificanceThis approach effectively addresses the issues of low-temperature operation, miniaturization, and long-term reliability. The proposed patch-antenna gas sensor is suitable for large-scale production owing to its use of industrial chemical vapor deposition technology and could be used to develop Internet-of-Things gas sensor nodes owing to its wireless propagation of electromagnetic waves with sensing information.

A Novel Flying Robot Swarm Formation Technique Based on Adaptive Wireless Communication using MUSIC Algorithm

This paper presents a novel technique to address the challenge of coordinating swarm flying robots in a leader-follower configuration. A combination of the Multi Signal Classification (MUSIC) estimation algorithm, based on a wireless MIMO array antenna, along with onboard robot control are used for precise route tracking of an individual robot. Employing an array antenna reduces energy consumption for followers in passive mode and reduces computational complexity when measuring the angles of leader angle interferences, which depends on the phase difference of the impinging signal on the antenna elements of the array. Additionally, the angles estimation and beamforming processes, utilizing MUSIC algorithm, form an inner loop that furnishes orientation angles in 3D (Azimuth and elevation angles) for both the leader and potential interference sources. The outer loop, contingent on the onboard controller and the robot's GPS system, enabling fine adjustments in angle and position relative to the leader's location. The simulation results illustrated the efficiency of the proposed technique in estimating the orientation angles of the leader and the interference sources. The technique robustness is confirmed through testing the performance on different trajectories. Where the follower perfectly generates a main radiation beam directed towards the leader, effectively mitigates interference signals from neighboring group leaders, and successfully tracks the leader path.

Finite Element Model Updating Method for Radio Telescope Antenna Based on Parameter Optimization with Surrogate Model

There are deviations between the radio telescope antenna finite element (FE) model, founded on the design stage, and the actual working antenna structure. The original FE model cannot accurately describe the antenna structure deformation characteristics under the environmental load, thereby compromising the accuracy of the active structural compensation. This article proposes an antenna FE model updating method founded on parameter optimization with a surrogate model. The updating method updates the modulus of elasticity parameters of different components of the antenna backup structure (BUS) to obtain finite element analysis (FEA) results consistent with the actual measurement of the antenna reflector surface shape. The surrogate model founded on the multi-quadratic radial basis function (RBF) improves the computational efficiency of FE model updating, replacing the complex and time-consuming finite element analysis and calculation process. This method is implemented on a radio telescope antenna with an aperture of 25 m. The results show a significant reduction in the mismatch between the antenna and the updated FE model. This method’s calculation time is significantly reduced compared with the updating method without using the surrogate model, with the RBF surrogate model taking 1% of the time of the finite element model in the FEA calculations. The proposed method can improve the antenna FE model calculation accuracy and significantly enhance the efficiency of FE model updating calculations. Thus, it can offer a reference for antenna engineering practice.

Development of an Adaptive Beamforming Algorithm for Signal Tracking and Acquisition in a Mobile Radio Antenna System

Development of an Adaptive Beamforming Algorithm for Signal Tracking and Acquisition in a Mobile Radio Antenna System

Coplanar waveguide fed inverted slot hybrid square ring antenna

ABSTRACT This paper presents a compact coplanar waveguide (CPW) fed inverted T slot loaded hybrid square ring antenna for Amateur radio (HAM) application. The CPW feed line is configured with unique characteristics: lower radiation leakage, wider bandwidth, and less dispersion than microstrip lines. The antenna is low-profile and inexpensive. The antenna design occurs in High-Frequency Structure Simulator (HFSS) simulation software and attains a S11 of −10 dB. The CPW-fed hybrid square ring antenna is considered in this research, and the antenna is embedded with inverted T slots. The antenna is constructed using a Flame Retardant 4 (FR4) substrate with a thickness of 1.4 mm and tangent losses of 0.019. The key parameters of gain, radiation pattern (RP), voltage standing wave ratio (VSWR), S11, and surface current (SC) are examined. The S11 of the designed antenna is −16.07 dB, VSWR is 1.37, and the gain is 3.6 under the operating frequency range of 2.45 GHz, and the designed antenna is suitable for HAM radio applications. The radiation pattern was analysed for the E and H planes under both the measured and the simulation scenarios. The simulation results are obtained via the HFSS platform, and the fabricated measurements are in accordance with each other.

Theoretical researches of the chiral metamaterial screen characteristics in the cellular radio

Metamaterial structures are currently being used to reduce the mutual influence of antennas and antenna arrays of different frequency ranges. In this work, the authors carried out studies of metamaterial screen designed for a resonant frequency of 900 MHz. The purpose of this work was the synthesis and theoretical studies of the characteristics of a screen made of chiral metamaterial in the cellular radio range. The results of studies were obtained to determine the natural resonant frequency of metamaterial screen when it is excited by a plane wave and a half-wave dipole. Frequency dependences of the isolation between two dipoles in the presence of metamaterial screen and without it were also obtained. It is shown that a metamaterial screen at the established resonant frequency provides an isolation of 25 dB. The screen synthesized and studied in this work can be used to reduce the influence of cellular radio antennas on other antennas present on a complex telecommunications objects.

A new approach for the numerical calculation of diffraction patterns using starshades

Context. We studied the imaging of exoplanetary systems using starshades, which are externally occulted coronagraphs in space. Aims. We provide a new method for precisely evaluating the stray light due to the star and a rapid calculation of the point spread functions in the presence of vignetting effects from the external occulter. Our study used shaped occulter configurations published in the literature, in particular, the SISTER NI2 and NW2 systems. Methods. The wavefront at the telescope aperture was computed using the classic Fresnel filtering method. The Fourier transform of the occulter was obtained with the highest possible precision using an approach initially developed for radio antennas, known as the polygonal shape factor. Results. We show that the Fresnel diffraction for a finite spatial field operates at very low frequencies only, and that it is sufficient to calculate the Fourier transforms there. Diffraction patterns computed numerically fully agree with theoretical predictions. The central parts of diffractions of petal and apodized occulters are identical over a large central area that increases in size with the number of petals. These diffraction patterns are used to compute the point spread functions. We computed the stray light for a non-point source star; this shows that starshades are not sensitive to star leakage, with a star diameter limit for a given configuration. We also computed signal-to-noise ratios for a perfect experiment limited by photon noise.

INVESTIGATION OF BROADER BANDWIDTH ELLIPTICAL DIPOLE ANTENNA PERFORMANCE PARAMETERS FOR 5G, KU AND KA-BAND APPLICATIONS: DIELECTRIC CONSTANT EFFECTS

This study presents an examination of the design and evaluation process of an elliptical dipole antenna operating at the design frequency of 5 GHz. Initially based on conventional dipole antenna principles, the antenna's design is iteratively refined through bandwidth enhancement techniques, resulting in the emergence of ultra-wideband characteristics. Notably, the modified antenna design features a distinctive notch band spanning from 4.21 to 10.06 GHz, positioning it as a versatile solution suitable for applications across the mid-band of 5G, as well as the full Ku and partial Ka bands, encompassing frequencies from 27 GHz to 31 GHz. Furthermore, this study investigates the impact of varying dielectric constants on antenna parameters, shedding light on a critical aspect often overlooked in conventional dipole antenna calculations. Through systematic analysis, it is revealed that a dielectric constant of 4.3, aligned with the commonly used low-cost epoxy-based FR-4 material, yields optimal performance. While higher dielectric constants broaden the antenna's characteristics, lower values are found to enhance communication efficiency, thus offering potential benefits in terms of power consumption and cost savings. The detailed examination and findings presented in this study enrich the understanding of antenna design principles and provide valuable guidance for future research and practical applications in the field of wireless communication and antenna engineering.

Broadband four-shoulder sine antenna of radio monitoring and direction finding equipment with a note system of two orthogonally combined printed resistance transformers

Problem statement. The article presents material on the development of antennas used in radio monitoring and radio direction finding equipment of electronic warfare equipment. The basic requirements for the design and characteristics of antennas of radio monitoring and direction finding equipment are presented. Aspects of the fundamentals of the development of a four-arm broadband antenna powered by two orthogonally combined printed resistance transformers, which has not been used before, for the possibility of controlling polarization, are considered, the results of modeling the developed antenna are presented and recommendations for its use in the antenna array are given. Purpose. To develop a small-sized antenna that allows to increase the efficiency of the operation of radio direction finding and radio monitoring complexes in an ultra-wide frequency band, with a special power supply system of two orthogonally combined printed resistance transformers for the possibility of implementing polarization control. Results. Based on the methods of electrodynamic modeling, computational methods of technical electrodynamics, methods of full–scale experimental measurements of antenna characteristics and methods of computer processing of data of full-scale experimental measurements, an antenna has been developed that allows the control of amplitude, phase and polarization parameters in an ultra-wide frequency band. The developed antenna is based on a flat four-arm sine element with a power supply system of two orthogonally arranged printed resistance transformers. The resistance transformer significantly reduces the level of the reflection coefficient at the input and radiation losses. The use of this development in radio direction finding and radio monitoring complexes will reduce the number of sublattices of the antenna system due to the functioning of its elements in an ultra-wide frequency band. The practical significance lies in reducing the number of letters of radio direction finding antenna systems consisting of the developed antenna elements, minimizing the degree of distortion of ultra-wideband signals and ultrashort pulses of arbitrary (varying) polarization received by antenna devices and systems from the antenna presented in the article. The developed antenna and antenna devices based on it can be used for electronic warfare, as well as improving communication and remote control systems.

Multifunctional titanium co-doped ZnAl2O4V2O5 composite ceramic nanoparticles: Enabling enhanced performance for L, S, C, and X band communications

This paper investigates the potential of zinc aluminate (ZnAl2O4)-based microwave dielectric ceramics for use as materials in the 4–10 GHz band for patch antennas. Microwave dielectric nanoceramics (MDNC) play a vital role in the telecommunications industry, and ZnAl2O4 stands out as a particularly intriguing and promising nonmetal for wireless microstrip antennas. X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) assessments confirm the presence of both ZnAl2O4 and TiO2/V2O5, establishing a dual-phase system. Simultaneously, energy dispersive spectroscopy (EDS) is utilized to scrutinize the composite nanoparticles for functional groups, morphology, and elemental composition. The introduction of titanium dioxide/vanadium pentoxide results in a significant augmentation of both crystallite and grain sizes. The estimated size of the nanoparticles' crystallites is 19 nm, while the dielectric permittivity and dielectric loss range between 22.82 and 22, and 0.14 and 0.007, respectively. This paper presents the key parameters of the fabricated patch antenna, denoted as (1-x)ZnAl2O4x(0.6 wt%V2O5-0.4 wt%TiO2) (ZAVT). The antenna's performance is defined by a return loss (RL) of −44.69 dB, a bandwidth spanning 1.723 GHz, and a voltage standing wave ratio (VSWR) of 1.23, all observed consistently at an operational frequency of 8.73 GHz in both measured and simulated scenarios.

Synthesis and fabrication of proto-type microstrip patch antenna by using microwave dielectric ceramic nanocomposite material for C-band application

The microwave dielectric properties of Zn(1-x)TixAl2O4 (ZTA) ceramic nanomaterials were investigated with a focus towards their use as wireless antennas. The ZTA nanoparticles were prepared using the sol-gel technique at 700 °C for one hour. The inclusion of titanium decreased the nanomaterials' crystallite size and surface shape, which influenced their dielectric permittivity (εr). Based on the tested material and microwave antenna theory, ZTA was used to fabricate wireless patch antennas, which were then examined using a PNA series network analyzer. The measured results reveal that the return loss and impedance bandwidths of the antenna were −44.83 dB simulated and −34.88 dB measured, and 240 MHz for simulated and 220 MHz for measured, respectively. At 5.1 GHz operating frequency, the Zn0.94Ti0.06Al2O4-based patch antenna demonstrated an exceptional combination of return loss (-34.88 dB), compact size (9.3× 6.3 mm2), and broad bandwidth (220 MHz) as well as VSWR<2. Ultimately, the fabricated antenna showcases a gain of 4.24 decibels and a directivity of 5.97 decibels.

Pruning: a tool to optimize the layout of large scale arrays for ultra-high-energy air-shower detection

The deployment of several large scale arrays is envisioned to study astroparticles at ultra-high energies. In order to circumvent the heavy computational costs of exploring and optimizing their layouts, we have developed a pruning method. It consists in i) running a set of microscopic simulations and interpolate them over a dense, regularly spaced array of detection units, and ii) pruning the unnecessary units out of the layout, in order to obtain the shower footprint on a newly shaped layout. This method offers flexibility to test various layout parameters, instrumental constraints, and physical inputs, with a drastic reduction in the required CPU time. The method can be universally applied to optimize arrays of any size, and using any detection techniques. For demonstration, we apply the pruning tool to radio antenna layouts, which allows us to discuss the interplay between the energy and inclination of air-showers on the size of the radio footprint and the intensity of the signal on the ground. Some rule-of-thumb conclusions that can be drawn for this specific case are: i) a hexagonal geometry is more efficient than a triangular geometry, ii) the detection efficiency of the array is stable to changes in the spacing between radio antennas around 1000 m step size, iii) for a given number of antennas, adding a granular infill on top of a coarse hexagonal array is more efficient than instrumenting the full array with a less dense spacing.

Impact Evaluation of an External Point Source to a Generalized Model of the Human Neck

A methodical approach for assessing the effects of an external point source to a non-spherical model of the human neck is presented in this paper. The neck model consists of multilayered spheres to represent the skin, fat, muscle tissues, thyroid, and esophagus. The novel geometry enables the formulation of dyadic Green’s functions to accurately calculate the electric fields, considering the suitable surface boundary conditions and the superposition principle. Numerical outcomes for a Hertz dipole (i.e., a wireless network antenna) at the frequency of 2.4 GHz certify the benefits of the technique and elaborately describe the responsiveness of the neck/thyroid to the selected source.