Textile Antenna Research Articles (Page 1)

This paper presents a novel antenna miniaturization approach for wearable applications, based on resonant current path length manipulation using T-shaped slots without compromising performance. A square microstrip textile antenna, initially designed for 5.8 GHz operation, undergoes modifications with T-shaped slots of varying lengths (11, 22, and 28 mm). These slots extend the effective current path, thereby reducing the resonance frequency to 5.2, 3.5, and 2.4 GHz, respectively, resulting in an 84% reduction in antenna size. The novelty of this work combining slot-based miniaturization with Machine Learning (ML) driven optimization. ML models, including Decision Tree (DT), Linear Regression (LR), Random Forest (RF), Gradient Boosted Tree (GBT), and Support Vector Machine (SVM), are evaluated using Root-Mean-Square Error (RMSE), Mean Absolute Error (MAE), and correlation values. Among the models, Decision Tree demonstrates superior accuracy with RMSE = 0.023, MAE = 0.019, and a correlation value of 0.998, demonstrating that ML can effectively support the design process, reduce iterative simulations. The combined slot-based miniaturization and ML-driven optimization framework provides a compact, high-performance solution for sub-6 GHz wearable antennas, offering both practical manufacturability and efficient design.

Abstract This paper presents the design and analysis of the Triple band Circular Quarter Mode Substrate Integrated Waveguide (QMSIW) 1 × 2 MIMO antenna for sub-6 GHz 5 G wireless applications. The antenna operates at three distinct frequencies those are 3.57GHz, 4.41GHz and 5.43 GHz respectively. The 3.57 GHz used to operate for WiMAX, 5 G, and Fixed Wireless Access, the 4.41 GHz, is often used for specific satellite uplink/downlink operations, Radar Systems and the third one 5.43 GHz is used for Wi-Fi, DSRC, and WLAN systems. The proposed architectural design underwent simulation utilizing electromagnetic (EM) tools to the extract results, followed by antenna fabrication and measured results, it was observed that there is a close match between the simulation, measured results and validated results. The measured, simulation gain values are 5.092dBi,4.98dBi at 3.57 GHz, 4.51dBi,4.6dBi at 4.41 GHz and 3.075dBi,3.06dBi at 5.43 GHz frequency, while also demonstrating satisfactory isolation between the ports, quantified as being less than −15 dB. The characteristic parameters of the MIMO antenna, including a diversity-gain (DG) surpassing 9.95 dB (>9.95 dB), alongside an envelope-correlation-coefficient (ECC) of less than 0.0001, Mean effective gain (MEG) lies between − 3 dB to − 4 dB, among any two radiating elements at every operational frequency, indicate that the antenna has been meticulously designed.

Hydrogels have attracted attention as highly biocompatible supporting materials for wearable devices. An antenna is a key component for wireless transmission of information collected by the devices worn on the human body. Furthermore, integrating antennas into the devices eliminates the need for external wiring, which could obstruct the movement of the human body. In this study, we demonstrated the fabrication of planar conductive structures by laser-induced graphitization of tannic acid-containing alginate hydrogels and the fabrication of microstrip patch antennas (MPAs) using the fabricated structures. In a single laser scan onto the hydrogels, cracks were formed in the fabricated structures. For the fabrication of continuous planar structures, we used a method leveraging the water absorption property of hydrogels. By the method, in which an aqueous solution of tannic acid was added to the structures, followed by rescanning the laser beam to convert tannic acid to graphitic carbon, the number of cracks decreased. Additionally, it is confirmed that the fabricated structures can be applied to the radiation patches of hydrogel-based MPAs. A decrease in the resonant frequency of the fabricated MPAs corresponding to the decrease in the number of cracks is observed.

ABSTRACTMicrostrip patch antenna (MPA) single‐element, half‐array, and multiple‐input multiple‐output (MIMO) designs, with an overall MIMO antenna size of 32.02 × 32.02 mm2, are built and analyzed in this study. The bandwidth of 4.12 GHz and the band of frequencies 25.605–29.727 GHz are the values used in the simulation. Rogers RT/duroid 5880, a low‐loss dielectric material, is used in the antenna's fabrication. This material has a dielectric constant of 2.2, a tangent loss of 0.0009, and an ultrathin height of 0.8 mm. The analogous model of the proposed MPA is constructed using an advanced design system (ADS) in contrast to the reflection coefficient gained using CST. The return loss of the prototype is also measured and is in contrast to the return loss seen in CST simulations. In the end, 120 data samples are collected through the simulation by using CST MWS, and five machine learning (ML) approaches, such as Nonparametric regression, random forest regression (RFR), decision tree regression (DTR), support vector regression model (SVRM), and extreme gradient boosting (XGB) regression, are implemented to evaluate the efficiency of the patch antenna. Mean square error, mean absolute error, root mean square error, R square, and the variance score are used to assess the efficacy of the five ML models. Nonparametric Regression outperforms the other ML models in terms of prediction accuracy (MSE = 2.31%, MAE = 1.77%, RMSE = 3.33%, R square = 94.28%, and var. score = 95.62%). This article describes analyzing the constructed antenna's performance by a combination of modeling, measurement, building the RLC equivalent circuit model, and incorporating machine learning approaches.

This paper presents triple-band antenna design geometry for textile antenna applications. The proposed antenna utilises the inherent conformal features of Jeans as the substrate and a conducting surface with flexible metal as the radiating surface. The proposed antenna geometry is simple in structure yet complicated in dimensions as it is susceptible to radiation characteristics. The proposed triple band antenna covers the operating frequency ranges notably, 2.3183-2.4465 GHz (128 MHz), 3.2240 GHz-3.9902 GHz (Bandwidth of 766 MHz) and 5.1858-5.6042 GHz (Bandwidth of 418 MHz). The bands of operation are suitable for WLAN, WiMAX and IoT applications respectively. The final outer dimensions of the proposed compact triple band antenna is 20 mm x 50 mm x 0.254 mm with Jeans of thickness of 10 mils (0.254 mm) used as the substrate. The triple band antenna is modelled on the efficient CAD tool embedded in the CST in which the simulations are carried out and analysis is performed using the generated reports like reflection coefficient, VSWR and radiation patterns. The simulations and measurement results are good agreement in terms of bandwidth (BW), Return Loss (S11) and Radiation pattern (RP), bending analysis and Specific Absorption rate (SAR).

This study presents a compact, wideband fractal antenna fabricated using silver nanoparticles (AgNPs) and screen-printing technology. The antenna consists of a decagonal monopole patch and a mesh ground plane, both printed on a transparent polyethylene terephthalate (PET) substrate. The proposed antenna has a compact size of 18 × 16 × 0.55 mm3, achieved by stacking two PET layers joined using double-sided tape. The antenna covers both C- and X-bands, with measured optical transmittance of 68.1% and radiation efficiency of 72%. The simulated −10 dB bandwidth (without bending) spans 4–10.8 GHz and 11.2–12.5 GHz, while the measured −10 dB bandwidth is 3.8–11.2 GHz without bending, 3–11.4 GHz at 30° bending, and 3–11.2 GHz at 45° bending, confirming that there was stable performance under flexure. The conductive patterns were formed using silver nanoparticle paste with a sheet resistance of 0.2 Ω/sq, followed by annealing in a vacuum oven at 140 °C for 20 min. The proposed antenna was tested under 30° and 45° bending, and the measured S11 remained stable, confirming flexibility. The use of a flexible, optically transparent PET substrate enables installation on curved or see-through surfaces. Combining compact size, wideband performance, cost-effective fabrication, and optical transparency, the antenna demonstrates strong potential for application in X-band radar, C-band satellite communications, and S-band Wi-Fi.

A novel hierarchical sectorized neural network module for a fast direction of arrival (DoA) estimation (HSNN-DoA) of the signal received by a textile wearable antenna array (TWAA) under strong noise conditions is presented. The developed DoA module accounts for variations in antenna element gain, inter-element spacing, and resonant frequencies under the conditions of textile crumpling caused by the motion of the TWAA wearer. The proposed model consists of a sector identification phase, which aims to determine the spatial sector in which the radio gateway (RG) is currently located based on the elements of the spatial correlation matrix of the signal sampled by the TWAA, and a DoA estimation phase, which aims to accurately determine the angular position of the RG in the azimuthal plane. The architecture of the HSNN-DoA module, with different time window lengths in which angular position of RG is recorded, is investigated and compared with the DoA module based on a stand-alone MLP network and the corresponding Root-MUSIC DoA module in terms of accuracy and speed of DoA estimation under variable noise conditions.

Microstrip patch antennas (MPAs) are widely used and researched due to their compact size and ease of fabrication. This review presents a comparative analysis and bibliometric review of rapid prototyping techniques employed in the fabrication of MPAs, with a focus on identifying emerging trends and proposing a hybrid approach for enhanced scalability and efficiency. Furthermore, the study investigated the application of rapid prototyping technologies, specifically 3D printing and xurography, in the fabrication of MPAs. Using VOSviewer software, a bibliometric analysis was conducted on 2545 research articles published between 2000 and 2021, extracted from the Scopus database. The aim was to analyze the evolution and adoption of additive manufacturing and rapid prototyping techniques—specifically in the context of MPAs—and to evaluate research productivity based on keyword co-occurrence and thematic evolution in the field. The analysis revealed that while 3D printing has gained significant attention in antenna fabrication, xurography remains underutilized in MPA development. From the relevant keywords identified, “microstrip antennas” and “microstrip patch antenna” demonstrated strong co-occurrence, whereas “xurography” displayed limited connectivity, suggesting a gap in research. Xurography, often used in microfluidics, presents a promising approach for low-cost, eco-friendly antenna fabrication. The analysis highlights a significant opportunity for further research to explore xurography’s potential in antenna design and fabrication, addressing current limitations in cost-effectiveness and scalability. Bridging this research gap can advance the development of MPAs for both academic and industrial applications, making them more accessible and sustainable.

Structural design and model fabrication of a novel double-ring deployable mesh antenna

Abstract This study evaluates the electromechanical performance of a multifunctional antenna system integrated into Kevlar fabric and composite structures, with an emphasis on wireless signal transmission during tensile and bending loads. Instead of conducting a full electromagnetic characterization, wireless power transmission was used as a surrogate signal to simplify electrical analysis and enable consistent performance tracking during mechanical deformation. Power retention served as the primary metric to assess signal stability under loading, while Digital Image Correlation was used to monitor strain distribution. The embroidered Kevlar-based antenna maintained stable power transmission up to 2.2% tensile strain, with complete signal loss occurring at approximately 11% strain. When integrated into a composite structure, the antenna retained signal transmission up to 1.4% strain, corresponding to mechanical failure of the composite. During flexural testing, signal performance declined progressively with increasing curvature but remained fully recoverable below 2% flexural strain. Beyond this range, irreversible damage to the composite resulted in permanent degradation of signal transmission. These results highlight the antenna’s performance under axial loading and its limitations under bending, offering insights into its mechanical-electrical coupling behavior. Full stress–strain curves are presented for both fabric and composite specimens, showing good repeatability and statistical consistency across samples. While this feasibility-focused study does not include traditional electromagnetic parameters such as S-parameters, return loss, or gain, it establishes a quantitative foundation for the continued development of embedded textile antenna systems in structurally demanding applications.

With the advancement of beyond 5G technologies, miniaturizationof electronic devices, and proliferation of Internet of Things applications,transparent and flexible materials such as cycloolefin polymers (COPs)have garnered increasing attention as candidate antenna substrates.However, the inherent lack of chemically reactive functional groupson COP surfaces poses challenges for their use in antenna and circuitboard fabrication. In this study, we propose a surface modificationstrategy that combines mild low-pressure plasma treatment with thesubsequent introduction of functional molecular layers to enhanceinterfacial adhesion between copper (Cu) and COP substrates. Importantly,this approach maintains the inherent low surface roughness of COPwhile increasing chemical reactivity. We systematically investigatedthe influence of plasma treatment time (30 s to 10 min) on the COPsurface properties, molecular layer bonding, and the adhesion performanceof Cu/COP. A peel strength exceeding 1.2 kN/m was achieved when plasmatreatment time was kept below 5 min, and adhesion values above 1.0kN/m were retained even after thermal aging at 120 °Cfor 7 days. To clarify the mechanisms underlying adhesion performance,we thoroughly characterized the chemical structure at the Cu/COP interfaceand evaluated the effects of plasma treatment on both interfacialstrength and thermal durability. Notably, atomic force microscopy–nanoscaleinfrared spectroscopy (AFM-nanoIR) was employed to directly probechemical changes at the Cu/COP cross-section, providing submicronspatial resolution. This analysis revealed that oxidation at the interfaceparticularlyintensified after thermal exposurewas a primary factor contributingto interfacial degradation and reduced adhesion performance. Thesefindings highlight the critical role of plasma-induced surface activationin enhancing metal–polymer adhesion and offer insights intothe limitations of current modification strategies. The results furthersuggest potential strategies for improving interfacial reliabilityin chemically inert polymer systems, paving the way for their broaderuse in diverse metal adhesion applications.

The advancement of wearable technologies has resulted in significant interest in GNSS-integrated textile antenna development. Although existing literature surveys predominantly concentrate on flexible non-textile antenna systems operating within UHF and 5G frequency spectra, systematic investigations of textile-based antenna configurations in the 1–2 GHz GNSS band have been relatively scarce. Contemporary GNSS textile antenna architectures primarily target GPS frequency coverage, while the global proliferation of BeiDou Navigation Satellite System (BDS) infrastructure necessitates urgent development of BDS-compatible textile antenna solutions. This review methodically examines the structural configurations and radiation characteristics of 1–2 GHz textile antennas, bandwidth enhancement techniques, miniaturization methodologies, and gain optimization approaches, along with material selection criteria and manufacturing processes. Technical challenges persist in simultaneously achieving broadband operation, compact dimensions, and elevated gain performance. Primary manufacturing approaches encompassing laminated fabric assemblies, printed electronics, and embroidered conductive patterns are analyzed, while existing methodologies exhibit limited capacity for seamless garment integration. Despite remarkable progress in conductive material engineering, dielectric property modification studies demonstrate insufficient theoretical depth. Comprehensive mitigation strategies for multifaceted operational environments involving human proximity effects, mechanical deformation, and variable meteorological conditions remain notably underdeveloped. This comprehensive analysis aims to establish a foundational framework for next-generation BDS-oriented textile antenna development.

The popularity of wearable antennas has grown significantly in recent years due to their lightweight, low-cost, compact, and flexible nature, making them ideal for wireless communication in various environments. When integrated with the human body, these antennas must be lightweight, flexible, low-profile, and capable of operating near the body without performance degradation. Designing wearable antennas becomes particularly challenging when incorporating textile substrates, high-conductivity materials, and accounting for body coupling effects. This manuscript proposes an Innovative Wearable Microstrip Patch Antenna with a Dual-Path Multi-Scale Attention Guided Network (IWMS-PA-DPMSAGN). The design incorporates an Annular Koch Snowflake Slot Structure (AKSSS) into the Microstrip Patch Antenna (MPA) to enhance bandwidth. A Dual-Path MultiScale Attention Guided Network (DPMSAGN) is utilized to streamline the antenna design process and predict its performance accurately. The proposed antenna is fabricated using a flexible Rogers RT5880 substrate, making it suitable for wearable applications. Compared to the existing methods, the IWMS-PA-DPMSAGN achieves bandwidth improvements of 26.08%, 19.09%, and 18.14% over the Eye Bolt Shape Slotted MPA Design with Return Loss Prediction using ML (EBSMSA-RLP-ML), the Optimized Wearable Textile Antenna Using Surrogate Ensemble Learning for ISM On- Body Communications (OWTA-SEL-ISMBC), and the Compact Textile Monopole Antenna for Monitoring Bone Fracture Healing using an Unsupervised Machine Learning Approach (CTMA-MHBF-UML), respectively.

This paper presents the design, simulation, and fabrication of a horn antenna integrated with a dielectric lens for focusing RF energy at 10 GHz. The antenna system combines established electromagnetic principles with 3D printing techniques to produce a cost-effective alternative to commercial focusing antennas. The design methodology employs the lensmaker’s formula and Snell’s law to determine lens curvature for achieving a specified focal length of 100 mm. COMSOL Multiphysics simulations indicate that adding a PTFE lens increases power density concentration compared to a standard horn antenna, with a simulated focal point at approximately 100 mm. Surface roughness analysis based on the Rayleigh criterion supports 3D printing suitability for this application. Experimental validation includes radiation pattern measurements of the antenna without the lens and power density measurements versus distance with the lens, both showing good agreement with simulation results. The measured focal length was 95±5 mm, closely matching simulation predictions. This work presents an approach for implementing focused RF delivery solutions for medical treatments, wireless power transfer, and precision sensing at significantly lower costs than commercial alternatives.

This paper presents an enhanced circularly polarized (CP) all-textile antenna using a metasurface (MS) and slot-patterned ground (SPG) for 5.8 GHz industry, scientific, and medical (ISM)-band applications in off-body communications. The 3 × 3 MS, capable of converting the incident wave into an orthogonal direction with equal magnitude and a 90° phase difference, converts the linearly polarized (LP) wave, radiated from the fundamental radiator with a corner-truncated slot square-patch configuration, into being CP. The SPG, consisting of periodic slots with two different sizes of corner-truncated slots, redistributes the surface current on the ground plane, enhancing the axial ratio bandwidth (ARBW) of the proposed antenna. The novel combination of MS and SPG not only enables the generation and enhancement of CP characteristics but also significantly improves the impedance bandwidth (IBW), gain, and radiation efficiency by introducing additional surface wave resonances. The proposed antenna is composed of a conductive textile and a felt substrate, offering comfort and flexibility for applications where the antenna is placed in close proximity to the human body. The proposed antenna is simulated under bending in various directions, showing exceptionally similar characteristics to a flat condition. The proposed antenna is fabricated and is then verified by measurements in both free space and a human body environment. The measured IBW is 36.3%, while the ARBW is 18%. The measured gain and radiation efficiency are 6.39 dBic and 64.7%, respectively. The specific absorption rate (SAR) is simulated, and the results satisfy both US and EU safety standards.

Microwave antennas are critical to the advancement of high-frequency communication systems, enabling long-distance transmission and reception of electromagnetic signals. This literature survey reviews the evolution, design principles, and performance metrics of various microwave antenna types, including horn antennas, parabolic reflectors, microstrip patch antennas, phased arrays, and MIMO systems. The study spans frequencies from 300 MHz to 300 GHz and highlights the trend toward miniaturization, enhanced bandwidth, higher gain, and greater radiation efficiency. These improvements support diverse applications such as satellite communication, radar, medical imaging, and 5G networks. The survey emphasizes innovations in antenna materials, structural design, and fabrication, aiming to meet modern demands for compactness, adaptability, and efficiency. This foundational overview aids in understanding current challenges and future directions in microwave antenna development.

Handset Reference Antenna Array Design, Fabrication, and Application to Hand Effect Study at Sub-THz

Holographic metasurface antennas (HMAs) have gained significant attention for their ability to achieve dynamic beam steering, high gain, and compact integration in high-frequency communication systems. This paper presents the design, analysis, and fabrication of a holographic metasurface antenna operating at the 24 GHz frequency band, targeting applications such as automotive radar, wireless communications, and satellite links. The proposed antenna employs a metasurface layer to manipulate electromagnetic wavefronts based on holographic principles, enabling efficient beamforming and reduced sidelobe levels. Full-wave electromagnetic simulations are conducted to optimize the metasurface structure, ensuring enhanced radiation efficiency and wide-angle beam scanning. A prototype is fabricated using PCB-based manufacturing techniques, and its performance is experimentally validated. Measurement results demonstrate a high-gain radiation pattern, effective beam steering capabilities, and improved efficiency, making the proposed HMA a promising candidate for next-generation high-frequency communication systems.

This paper presents the design of a flexible dual-band textile antenna incorporating a defected ground structure (DGS) for wireless applications. The antenna is fabricated on a jeans-based textile substrate (εr = 1.7, thickness = 3.24mm), offering mechanical flexibility and conformability suited for wearable and portable platforms. A slot-loaded radiating patch combined with a DGS achieves resonant operation at 2.4GHz and 3.5GHz, targeting ISM and 5G mid-band communications. Strong impedance matching is observed, with simulated input impedances closely aligned to the 50Ω standard. Measured gains of 5.38dB at 2.4GHz and 6.87dB at 3.5GHz are achieved under both flat and bent conditions, validated through full-wave simulations and experimental testing using a Vector Network Analyzer (VNA) and anechoic chamber. Specific Absorption Rate (SAR) analysis performed on multilayer human tissue phantoms confirms that SAR values remain below 1W/kg, ensuring compliance with international safety standards. The proposed design combines structural simplicity, spectral selectivity, and mechanical resilience, offering a promising solution for next-generation flexible and wearable wireless communication systems.

ABSTRACTThe design of an ultra‐wideband (UWB) multiple‐input multiple‐output (MIMO) antenna for smart fabric communications can significantly improve the reliability of wireless connections and overcome challenges such as channel fading and shadowing caused by the human body. This technology proves valuable for security applications, location tracking, and patient monitoring. Cotton fabric serves as the substrate material for the proposed textile antenna. With a connectivity‐aware graph neural network (CAGNN), a UWB MIMO antenna is designed with four octagonal radiators, each loaded with multiple slots, offering a frequency range of 2.9–12 GHz. The unit cell measures , and the MIMO antenna measures . Performance metrics, like channel capacity loss (CCL), diversity gain (DG), total active reflection coefficient (TARC), envelope correlation coefficient (ECC), and specific absorption rate (SAR), are considered. The efficiency of the proposed approach is compared with existing approaches. The proposed CAGNN‐DUWBMIMO technique is implemented. The proposed approach achieves 26.36%, 20.69%, and 30.29% better ECCs; 19.12%, 28.32%, and 27.84% better DGs; and 12.04%, 13.45%, and 22.80% better SARs compared with existing models: design with the analysis of a UWB MIMO antenna for smart fabric communications (DA‐UWBMIMO), design with the analysis of a UWB MIMO antenna for smart fabric communications (DDPT‐UWBMIMO), development including the comprehensive assessment of a double‐port textile UWB MIMO antenna for biomedical use (DDBW‐MIMOA), respectively.