Array Of Units Research Articles

Novel star fractal MIMO antenna integrated with a unique parasitic decoupler for enhanced 5G/IoT/UWB communication performance

Abstract This study focuses on the development, simulation, and experimental analysis of a two-port, fractal-inspired UWB antenna array for optimal deployment in 5G/IoT/UWB systems. The array is structured 1.57mm thick, dielectric FR4 material, encompassing a 38 × 66 mm2 area. The design includes two offset-fed pentagonal radiating patches defective with a 2nd iterative novel star-fractal pattern on its upper surface, which optimizes the array’s radiative properties and triggers a wide operating range of 3-14.6GHz with an impedance bandwidth ratio of 3.87:1. The application of unique star-fractal design contributes to 54.33% shrinkage of patch area in contrast to the typical pentagonal patch. The rear dielectric layer features a reduced ground plane embedded with novel parasitic and stub-loading decoupling structures (placed centrally) to significantly suppress the cross-coupling between the array units and minimize mismatch losses. Multiple diversity parameters are reviewed and are found to comply with their defined thresholds, demonstrating a favorable match between simulation and experimental findings. The array design effectively addresses the rising demand for compact solutions tailored for handheld devices, thus facilitating real-time operations in 5G/IoT frameworks.

Plasmonically enhanced solar-blind self-powered photodetector array utilizing Pt nanoparticles-modified Ga2O3 nanorod heterojunction

Low-dimensional Ga2O3 monocrystalline micro/nanostructures show promising application prospects in large-area arrays, integrated circuits, and flexible optoelectronic devices, owing to their exceptional optoelectronic performance and scalability for mass production. Herein, we developed an 8×8 array of high-performance solar-blind ultraviolet photodetectors based on Pt nanoparticles-modified Ga2O3 (PtNPs@Ga2O3) nanorod film heterojunction with p-GaN substrate serving as the hole transporting layer. The PtNPs@Ga2O3/GaN heterojunction detector units exhibit outstanding photovoltaic performance at 0 V bias, demonstrating high responsivity (189.0 mA/W), specific detectivity (4.0×1012 Jones), external quantum efficiency (92.4%), and swift response time (674/692 µs) under an irradiance of 1 μW/cm2 at 254 nm. Their exceptional performance stands out among competitors of the same type. In addition, the detector array demonstrated satisfactory results in a conceptual demonstration of high-resolution imaging, benefiting from the excellent stability and uniformity exhibited by its array units. These findings provide a straightforward and viable method for developing a high-performance solar-blind ultraviolet detector array based on low-dimensional Ga2O3 nanorod monocrystalline, demonstrating their potential advancement in large-area, integrable, and flexible optoelectronic devices.

Design and simulation analysis of a two-dimensional extended array structure

Abstract A compact and two-dimensional expandable extended array structure was designed to meet the electrical and structural compatibility requirements of a certain type of equipment. The transition from the distance between the RF component side RF channels A × B (mm) to the distance between the antenna array units a × b (mm) was achieved. The structural mechanical performance simulation was conducted. It was found that the deformation in the connector insertion direction was significant, which affected the reliability of the RF connection. Based on the simulation results, the original structural scheme was optimized and further improved to enhance the assembly, maintenance, and interchangeability of the extended array. The maximum structural deformation in the insertion direction of the RF connector was 0.19mm, which was reduced by 0.2mm compared to the previous optimized scheme with a structural deformation of 0.39mm. The large deformation area was significantly reduced. The stiffness of the structure was significantly improved, meeting the reliability requirements of multi-channel module RF blind insertion.

Calibrating position and orientation of multiple ultrasound phased array units using Bayesian optimization.

Airborne ultrasound phased arrays (AUPAs) generate non-contact tactile sensations and enable acoustic levitation with specific focus fields. Using multiple units together offers numerous advantages, such as increased stimulus intensity and the ability to overcome occlusion. The AUPA units are typically mounted on a fixed frame, with their poses manually measured using tools such as a ruler for calibration. However, to increase the degrees of freedom for these units, a more flexible calibration method is required. With a wavelength of 8.5 mm, a 4 mm deviation in propagation distance from the two phased arrays can weaken the pressure at the focus position. Hence, in this study, calibration based on pose and focus information obtained through image processing was performed. First, augmented reality markers are attached to each AUPA unit for rough estimation of pose parameters. Second, using these approximate poses, the pressure distribution generated on a specific plane is estimated through thermal imaging. Finally, Bayesian optimization is employed to efficiently explore the pose parameters to minimize the error between the desired position and generated focal point. This approach enables the efficient calibration of the relative poses of AUPA units, even when they are placed in challenging-to-measure locations.

Series-Fed Microstrip Patch Antenna Array with Additive-Manufactured Foldable Honeycomb-Shaped Substrate.

This paper presents a novel foldable S-band microstrip patch antenna array operating in the 2.4-2.45 GHz band. The substrate is designed to allow the array to be folded and arranged in tiles, forming a versatile, reconfigurable antenna array. Additive manufacturing is used to fabricate the substrate for ease of fabrication and flexibility in its design. The major challenge in this type of design is creating a proper method of feeding the elements while maintaining the array's optimal performance. A novel hinge design that can hold a coaxial cable for the series-fed array is introduced. The hinge provides the capability of folding the array from a flat orientation into various folded orientations. In this paper, a 2 × 1 microstrip array unit is presented as proof of concept. The antenna was fabricated and measured, and the results of the measurements are in close agreement with the simulations. The antenna can provide a gain as high as 7.72 dBi in flat conditions.

Millimeter wave MPA using Metamaterial-substrate Antenna array for Gain Enhancement

This paper presents a Millimeter wave Microstrip Patch antenna(MPA) with a metaplate which consists of Split Ring resonators(SRR) design. The gain and bandwidth of MPA are improved by using 4×3 array unit cells printed on both the sides of the metaplate. Simulation results show that the Gain of the antenna was increased by 4.82 dBi and 4.53 dBi, bandwidth was increased by 2.25% and 6.21% in CST and HFSS softwares respectively using the Metaplate along with the MPA. The center frequency of the proposed antenna is 28.5 GHz. Thus the proposed antenna has a very small size of 18×22 mm2 and is suitable for Millimeter wave applications.

Portable alkaloid discrimination via nanozyme-mediated colorimetric paper-based sensor array integrated with smartphone detection.

Apaper-based colorimetric sensor array mediated by a novel nanozyme (CuCo2O4) was developed using a screen-printing technology. The aim was to facilitate the identification of different kinds of alkaloids. Typically, three chromogenic substrates (3,3',5,5'-tetramethylbenzidine, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), and o-phenylenediamine) were selected as sensing elements, which can be catalyzed by a CuCo2O4 nanozyme with peroxidase-like activity to yield corresponding oxidized products, thereby inducing color changes. Owing to the varying inhibitory ability of different alkaloids on acetylcholinesterase (AChE), a decrease in choline (Ch) concentration occurs and subsequently results in the restoration of color within the units of sensor array. Color data can be transformed into hue information with a smartphone. The above color variations generated a unique "fingerprint" pattern on five alkaloids (berberine, palmatine, jatrorrhizine, eserine, and harmane), which can be successfully discriminated through linear discriminant analysis in the range0.2 to 20µM. Furthermore, the sensor arrays allowed successful discrimination of the above five alkaloids in Chinese herbal medicine samples and recognition of 22 blind samples. This work presents a novel nanozyme-based paper sensor array, which is a user-friendly and reliable platform for probing different alkaloids. In addition, the developed sensing strategy enables the identification of AChE-related diseases, positively contributing to the screening available of AD-associated drugs.

Manipulator with Integrated Flexible Tactile Sensing Arrays for Kiwifruit Ripeness and Size Classification.

Fruit grading for ripeness and size is an essential process in the supply chain. Incorrect grading can easily lead to spoiled and degraded fruits entering the market, reducing consumers' confidence in purchasing. At the same time, it is easy to cause the fruit supply chain to reduce profits, unreasonable resource allocation, and related practitioners' income. The current mainstream machine vision grading and manual grading in the production line have dilemmas such as susceptibility to environmental interference, inconsistent grading standards, high cost, and labor shortage. To overcome these problems, this study proposes an integrated flexible tactile sensing array (3 × 4) manipulator for efficient, stable, low-cost, and accurate ripeness and size grading of kiwifruit. The flexible sensing manipulator grasps the kiwifruit, detects the hardness of the kiwifruit by relying on tactile sensing, and determines the ripeness level based on the hardness. The size of the kiwifruit is also differentiated according to whether there is a significant change in the resistance of the topmost sensing unit of the flexible pressure sensor array. The 0, 1, 2, 3, 4, and 5 anomalies that may occur in actual production were tested and combined with machine learning KNN, SVM, and RF algorithms for data modeling and grading. The results show that the lowest accuracy of 0, 1, 2, 3, 4, and 5 possible outliers is 86.67% (KNN), 95.83% (SVM), and 92.5% (RF), respectively. KNN has the lowest classification effect, and SVM has the best. This study overcomes the drawbacks of inefficient destructive detection and unstable manual detection and makes up for the vulnerability of single machine vision to interference from environmental factors. This study can alleviate the challenges caused by fruit wastage and promote the sustainable production and consumption of the fruit industry chain.

Intelligent Song Recognition via a Hollow-Microstructure-Based, Ultrasensitive Artificial Eardrum.

Artificial ears with intelligence, which can sensitively detect sound-a variant of pressure-and generate consciousness and logical decision-making abilities, hold great promise to transform life. However, despite the emerging flexible sensors for sound detection, most success is limited to very simple phonemes, such as a couple of letters or words, probably due to the lack of device sensitivity and capability. Herein, the construction of ultrasensitive artificial eardrums enabling intelligent song recognition is reported. This strategy employs novel geometric engineering of sensing units in the soft microstructure array (to significantly reduce effective modulus) along with complex song recognition exploration leveraging machine learning algorithms. Unprecedented pressure sensitivity (6.9 × 103 kPa-1) is demonstrated in a sensor with a hollow pyramid architecture with porous slants. The integrated device exhibits unparalleled (exceeding by 1-2 orders of magnitude compared with reported benchmark samples) sound detection sensitivity, and can accurately identify 100% (for training set) and 97.7% (for test set) of a database of the segments from 77 songs varying in language, style, and singer. Overall, the results highlight the outstanding performance of the hollow-microstructure-based sensor, indicating its potential applications in human-machine interaction and wearable acoustical technologies.

Clinical and genetic evaluation of hereditary myopathies in an adult Saudi cohort

BackgroundDiagnosis of hereditary myopathy is often challenging owing to overlapping clinical phenotypes and muscle histopathological findings. This retrospective study aimed to identify the phenotypic and genotypic spectra of hereditary myopathies at a tertiary hospital in Riyadh, Saudi Arabia.MethodsWe reviewed the medical records of patients with hereditary myopathy who were evaluated between January 2018 and December 2022.ResultsEighty-seven patients (78 families) were included, two-thirds were men with a mean age of 35 (SD 14.2) years. Limb-girdle muscular dystrophy (LGMD) was the most prevalent clinical diagnosis (25 cases; 29%), of whom, a genetic diagnosis was achieved in 15 of 22 patients tested (68%). In genetically confirmed LGMD, the most prevalent disorders were dysferlinopathy (27%) followed by fukutin-related protein (FKRP) - related limb girdle muscular dystrophy (20%), sarcoglycanopathy (20%), lamin A/C related myopathy (13%), and calpain-3 myopathy (13%). In 26 patients with pathogenic/likely pathogenic variants, the genetic testing method was whole exome sequencing (WES) (42%), Next generation sequencing (NGS) (31%), and targeted single gene analysis (27%). The sensitivity of each genetic testing method was as follows: 100% for targeted single-gene analysis, 100% for targeted analysis of D4Z4 repeat array units, 88% for myotonic dystrophy protein kinase (DMPK) repeat expansion analysis, 42% for NGS-neuromuscular panel, and 46% for WES.ConclusionThe prevalent types of hereditary myopathies were consistent with those reported locally and internationally. This study highlights the diagnostic yield of various molecular genetic tests for the diagnosis of hereditary myopathy in an adult cohort and the need for improved access to advanced molecular testing in cases suspected to have facioscapulohumeral muscular dystrophy (FSHD) or mitochondrial myopathies.

Experimental research on the horizontally getting together behaviors of acoustically manipulated bi-particle

This study aims at the controllability of acoustically manipulated non-contact aggregation of bi-particle. Based on the acoustic wave radiation model of the transducer and the acoustic wave interference theory, the mathematical model between the spatial levitation point and the phase of the phased array ultrasonic array unit is established. A double-sided phased array test system was developed and the phase calculation algorithm for independently manipulating bi-particle was optimized. The algorithm is capable of independently distributing the energy applied to each levitation point. Through simulation and experiment, the horizontally aggregation characteristics of two levitated particles are investigated, and a interesting relationship between particles aggregation and standing wave phase difference is revealed, which follows the law of “attraction in the same phase but repulsion in the opposite phase”. By adjusting the tilt angle of the standing wave acoustic trap, the critical distance when particles to accelerate and collision is sharply reduced from 1.5λ to 0.5λ, which provides a new perspective and potential application path for acoustic manipulation technology.

A high‐power, high‐isolation, dual‐polarised planar phased array antenna

AbstractA high‐power, high‐isolation, dual‐polarised planar phased array antenna is presented. Based on a multi‐layer microstrip structure, two sets of polarisation ports are fed through orthogonal slot coupling, achieving high isolation and low cross‐polarisation. Double‐layer radiation patches and cavity interlayers are used to expand the bandwidth and increase the gain. Metal vias are added around microstrip feeders and between array units to suppress surface waves, thereby improving the scanning performance of the phased array. A smooth gradient microstrip structure is designed to improve the power capacity while realising broadband impedance matching. The measured results show that in the 8–10 GHz frequency band, the isolation of the dual polarisation ports is greater than 50 dB, and the impedance bandwidth reaches 22.2%, with active VSWR <1.5 when not scanning. Both sets of polarisation can achieve 2‐D beam scanning in the range of E‐plane ±20° and H‐plane ±40° without grating lobes, maintaining the scan loss below 2.4 dB, cross‐polarisation below −20 dB and active VSWR <2. Each unit achieves a high gain of 7.4 dB and large power capacity of 5 kW; so the entire 8 × 8 phased array can achieve a main lobe gain of 25.5 dB and realise high‐power directional radiation with the effective isotropic radiated power of 92.5 dBm. The proposed planar antenna has a low profile of 5.5 mm (0.17λ0).

Wideband Eight-Antenna Array Designs for 5G Smartphone Applications

This paper proposes a broadband eight-antenna array design suitable for Fifth Generation New Radio (5G NR) smartphone applications. To cover the 5G NR bands n77/n78/n79 (3300–5000 MHz) and 5G NR-U n46 band (5150–5925 MHz), the single antenna array unit applied is a modified loop antenna element (MLAE) that can generate three different loop modes. To yield good multi-input multi-output (MIMO) performances, the designed MLAE is further arranged as an eight-antenna array, and the experimental results show that the overlapping 6 dB bandwidth can cover the bands-of-interest (3300–5925 MHz) with good isolation and total efficiency of >10 dB and 51–84%, respectively. Finally, good MIMO performances, such as an envelope correlation coefficient (ECC) of lower than 0.1 and desirable channel capacity (CC) of 37–40 bps/Hz, were calculated across the bands-of-interest.

Cu2(OH)3NO3 nanozyme sensor array for the discrimination of multiple sulfides in food

In the food industry, sulfides are commonly used as preservatives and flavor regulators. However, long-term excessive intake of sulfides can lead to serious health problems. Therefore, developing efficient sulfide detection methods is particularly important. Here, we have effectively synthesized a novel bifunctional copper hydroxide nitrate (Cu2(OH)3NO3) nanozyme with outstanding peroxidase-like and laccase-like behaviors in basic deep eutectic solvents (DES). Because the various types of sulfides have diverse regulatory effects on the two catalytic behaviors of Cu2(OH)3NO3, a two channel nanozyme sensor array based on the peroxidase-like and laccase-like behaviors of Cu2(OH)3NO3 was constructed and successfully used for the identification of six kinds of sulfides (Na2S, Na2S2O3, Na2SO3, Na2SO4, NaHSO3, and Na2S2O8). Remarkably, the sensor array has achieved successful discrimination among six sulfides present in wine, egg, and milk samples. Finally, the sensor array has successfully distinguished and differentiated three actual samples (wine, egg, and milk). This study is of great significance in promoting the efficient construction of array units and improving the effective identification of sulfides in complex food samples.

Molecular Dynamics Analysis of Adhesive Forces between Silicon Wafer and Substrate in Microarray Adhesion

With the development of the electronics industry, the requirements for chips are getting higher and higher, and thinner and thinner wafers are needed to meet the processing of chips. In this study, a model of the adhesion state of semiconductor wafers in the stacking–clamping process based on microarray adsorption was established, the composition adhesion was discussed, the microarrays of different materials and pressures were experimentally studied, and a molecular dynamics model was established. The molecular dynamics analysis showed that the adhesion force was only related to the type of atom, and the applied pressure did not change the adhesion force. According to the simulation results, the tangential adhesion between the metal and the wafer is greater than that between the ceramic and the wafer, the adsorption force between the aluminum–magnesium alloy and the silicon wafer is shown in the normal direction, and the repulsion force between other materials and the silicon wafer is shown in the normal direction. During the pressure process, the metal is in the elastic deformation stage between the metal and the wafer, the wafer is plastically deformed in the silicon carbide ceramic and wafer, and the wafer is elastically deformed in the alumina ceramic and wafer. In this paper, the adhesion between the substrate and the wafer is studied, a method of constructing microarrays to enhance adhesion is proposed, and the tangential deformation of the array unit under pressure is studied, which provides theoretical support for increasing the adhesion by constructing microarrays.

Ultrafast Dynamics of Strong Near‐Field Coupled Localized and Delocalized Surface Plasmons

AbstractThis paper reports transient dynamics of strong near‐field coupling behavior of plasmons in a multilayer metal nanostructure that enables ultrahigh‐efficient optical switching. Particle plasmon on the top array units couples with localized/delocalized plasmons on the bottom Au film to produce dipolar and high‐order hybrid modes with nearly suppressed reflection. The mode coupling can be tuned from near‐field to far‐field regime readily mediated by the spacer thickness. The dipolar mode inherits the high dispersive property of the delocalized plasmon, but the higher‐order one shows limited dispersion. Transient spectroscopy illustrates both hybrid modes have a picosecond timescale redshift under on‐ and off‐resonance excitation. However, the higher‐order mode exhibits a longer decay lifetime than the dipolar one because of resonance characteristics and cavity properties. An ultrafast optical switching effect with a response time of τ = 3.2 ps and an ultrahigh efficiency of 5100 mOD mJ−1 cm2 is achieved under an extremely low pump fluence.

A nonlinear low frequency quasi zero stiffness vibration isolator using double-arc flexible beams

There is an increasing demand for integrated small vibration isolators in precision sensing instruments and medical equipment. Therefore, a quasi-zero stiffness (QZS) vibration isolator with double-arc flexible beams (D-AFB) is proposed. The QZS isolator consists of D-AFB units, the base, platform, fixture, guide rail, and linear bearing. The static performance of D-AFB is analyzed using the FEA method, and the QZS condition is obtained. The harmonic balance method (HBM) and the pseudo arc length method (PALM) are used to solve the dynamic equations of the nonlinear system, and the analytical solutions of displacement transmissibility and Force transmissibility are derived. In theory, the initial frequency is 77.6 % lower than that of the equivalent linear system. The QZS characteristic of D-AFB is verified by static experiment, and the low-frequency isolation performance of the QZS isolator is verified by dynamic experiment under constant amplitude and constant acceleration excitation. The D-AFB has a simple structure and can easily satisfy QZS conditions. So the D-AFB can be customized according to load requirements. Multiple vibration isolation loads can be obtained by adjusting the assembly of the D-AFB. The QZS isolator can adapt to load changes within 10 % and has an isolation effect on vibrations above 4 Hz. The idea of designing a QZS isolator with D-AFB as an array unit has a good research prospect and great application value in meeting the requirements of miniaturization and integration.

Experimental investigation of microchannel heat sink performance under non-uniform heat load conditions with different flow configurations

Cooling methods for multiple hotspots with high heat flux pose a reliability threat to electronic devices. This study investigates the microchannel-based heat sink performance under various non-uniform heat load conditions for different geometry with three different flow configurations (I, U and Z). An in-house designed Heater Array Unit (HAU) facilitates the generation of both uniform and non-uniform heat loads using a heater power supply. Two different microchannel geometries were employed, namely, microchannel-1 (MC-1) with channel and fin widths of 0.6 mm and 0.33 mm, respectively, and MC-2 with dimensions of 0.64 mm and 0.572 mm. Each microchannel incorporates three manifold configurations (I, U, and Z). Each flow configuration is regulated by flow control valves. Various non-uniform heat load patterns were considered, including streamline, non-streamline, and across-streamline conditions. To assess the thermal performance of the heat sinks the parameters used are thermal resistance (Rth), Nusselt number (Nu), and temperature non-uniformity (Ѱ). Experimental findings indicate that the MC-2 design with an I flow configuration is more suitable for uniform heat load conditions. On the contrary, for some non-uniform heat load cases MC-1 also showed up as a suitable design over MC-2.

Reliability evaluation of spacecraft power generation performance with competitive failure processes under irradiation

AbstractThe performance of space power systems is crucial for space products as it determines the operational capabilities, endurance, and efficiency of satellites, spacecraft, and other extraterrestrial devices. Unlike reliability analysis in aerospace systems, studying spacecraft power generation performance requires consideration of both hardware and software aspects. Existing failure models do not fully capture the self‐recovery process of control programs. Therefore, this study presents an impact degradation model for space power systems that incorporates competitive failures under irradiation conditions. The model analyzes solar arrays and power controllers to derive a performance degradation model by considering the defect formation mechanism of amorphous semiconductor materials. Additionally, two shock types are defined based on redundancy backup in power controllers and scrubbing frequency in field‐programmable gate array (FPGA) units. Within the case analysis section, the research meticulously investigates and elucidates the correlation probabilities among varying proton irradiation doses, scrubbing frequencies, and the aforementioned shock types.

Nanocellulose-Enhanced, Easily Processable Cellulose-Based Flexible Pressure Sensor for Wearable Epidermal Sensing.

Flexible pressure sensors (FPSs) based on biomass materials have gained considerable attention for their potential in wearable electronics, human-machine interaction, and environmental protection. Herein, flexible silver nanowire-dual-cellulose paper (SNdCP) containing common cellulose fibers, cellulose nanofibers (CNFs), and silver nanowires (AgNWs) for FPSs was assembled by a facile papermaking strategy. Compared with bacterial cellulose (BC) and cellulose nanocrystals (CNCs), CNFs possess better dimensions and reinforcement, which enables the composite paper to exhibit better mechanical properties (tensile stress of 164.65 MPa) and electrical conductivity (11600 S·m-1), providing more possibilities for FPSs. Benefiting from these advantages, we construct an easily processable and sensitive human-interactive FPS based on a composite paper with high sensitivity (0.050 kPa-1), fast response/recovery time (158/95 ms), and exceptional stability (>1000 bending cycles), capable of responding to finger motions, voice recognition, and human pulses; through further employment as the array unit and a control circuit, the observed highly adaptive mechano-electric transformability and functions are well maintained. Overall, a facile and versatile strategy with the potential to provide clues for the fabrication of cellulose-based FPSs with outstanding performance was introduced.