{"title":"Implementation and Performance Analysis of RTK-GNSS in Wearable Devices for Athletes in Harsh Environments","authors":"Mingu Kim, Bit Kim, Chulwoo Park, Jinsung Yoon","doi":"10.1049/ell2.70289","DOIUrl":"https://doi.org/10.1049/ell2.70289","url":null,"abstract":"<p>This study presents the performance analysis of RTK-GNSS (real-time kinematic global navigation satellite system) mounted on wearable devices for athletes in harsh environments. GNSS signal can deteriorate by obstacles, i.e. stadium roofs, due to the high GDOP (geometric dilution of precision). RTK-GNSS is used to overcome harsh environment problems in this study. Hardware experiments are performed to analyse the performance of RTK-GNSS in sports wearable devices in harsh environments. The full pitch tracking test results of a wearable device equipped with RTK-GNSS demonstrate the best performance among three different wearable devices in a harsh environment; the maximum positioning error of 1.56 <span></span><math>\u0000 <semantics>\u0000 <mi>m</mi>\u0000 <annotation>$text{m}$</annotation>\u0000 </semantics></math> is approximately 3–30 times smaller than that of wearable devices equipped with stand-alone GNSS. The distance test results of the wearable device equipped with RTK-GNSS validate the most accurate performance, 98.97<span></span><math>\u0000 <semantics>\u0000 <mo>%</mo>\u0000 <annotation>$%$</annotation>\u0000 </semantics></math>, compared to the true value in harsh environment.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70289","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Murad Khan, Mohammed Faisal, Abdullah Alharbi, Muhammad Diyan
{"title":"Energy Efficient Communication in Bluetooth 5.3 Using Fine-Tuned Dynamic Subrating Interval Optimization","authors":"Murad Khan, Mohammed Faisal, Abdullah Alharbi, Muhammad Diyan","doi":"10.1049/ell2.70290","DOIUrl":"https://doi.org/10.1049/ell2.70290","url":null,"abstract":"<p>Bluetooth 5.3 features, including connection subrating and low energy (LE) power control, enhance energy efficiency in internet of things (IoT) devices. However, optimizing energy consumption remains challenging in dynamic environments with varying traffic loads. This research presents a fine-tuned dynamic subrating interval optimization (FINE-DIO) approach, supported by an analytical model, to improve energy usage, communication latency, and packet delivery in Bluetooth 5.3 devices. The model evaluates energy consumption across active, idle, sleep, and advertising states, utilizing adaptive connection subrating and LE power control. The optimization process employs iterative fine-tuning, utilizing gradient-based adjustments and performance metrics such as latency and packet delivery ratio (PDR) to achieve the optimal balance between energy efficiency and communication reliability. The simulations confirm the effectiveness of dynamic subrating and periodic advertising optimization across various IoT applications. The results indicate that FINE-DIO achieves up to 15% energy savings, a 10–15% improvement in PDR, and a 20–25% reduction in communication latency, particularly in high-data-rate and interference-heavy environments.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70290","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Age of Information Violation Probability in a Multi-Source Information Update System With a Shared Channel","authors":"Hyungkuk Yoon, Bara Kim, Jeongsim Kim","doi":"10.1049/ell2.70261","DOIUrl":"https://doi.org/10.1049/ell2.70261","url":null,"abstract":"<p>We investigate the age of information (AoI) violation probability in an information update system with multiple sources sharing a channel with an infinite-capacity buffer under non-preemptive policies. A simple and accurate approximation formula for the AoI violation probability is derived, and numerical examples confirm its high accuracy.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70261","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michele Marrella, Manuela La Rosa, Alfio Dario Grasso, Giovanni Sicurella
{"title":"A Low-Power GaN Shift Register in GaN Monolithic Technology","authors":"Michele Marrella, Manuela La Rosa, Alfio Dario Grasso, Giovanni Sicurella","doi":"10.1049/ell2.70272","DOIUrl":"https://doi.org/10.1049/ell2.70272","url":null,"abstract":"<p>Gallium Nitride (GaN) semiconductor technology is being continuously advanced due to its favorable electrical and physical properties, particularly for high power switching uses. Consequently, there is an increasing demand for circuits using this technology, which necessitates monolithic implementation to maximise integration benefits. The development of integrated devices in GaN technology calls for auxiliary circuits, both digital and analogue, to accompany power circuits. A limitation of this technology is the lack of availability of the <i>p</i>-type transistor used in conventional analogue and digital design. In this paper, fundamental digital circuits have been designed with the intent to create digital memory circuits for data storage. The main goal is to reduce overall power consumption with custom-tailored solutions. Basic digital and analogue circuits have been analysed and optimised regarding power consumption efficiency and adaptability to power supply and temperature changes. A novel shift register topology in GaN monolithic technology from STMicroelectronics has been developed and tested through simulations.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70272","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143914196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Novel Dynamic Model Selection Approach for Image Object Detection","authors":"Ye Liu, Keyu Wu, Zhong Liu","doi":"10.1049/ell2.70263","DOIUrl":"https://doi.org/10.1049/ell2.70263","url":null,"abstract":"<p>Model selection is crucial for image object detection, enabling the selection of the best model for varying tasks. This paper introduces a novel dynamic model selection approach that adapts to underlying scenarios. The problem is formulated as a joint clustering and model assignment task, where clustering reveals the data's inherent structure, and the best model is assigned to each cluster. To solve this, we propose a spatial structure-preserving genetic algorithm, an efficient optimization method that integrates spatial information into genetic operations, ensuring faster and more stable convergence. Experimental results show that our approach outperforms individual models, highlighting the effectiveness and efficiency of dynamic model selection.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70263","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143905332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Paulo Olavo Lima Neves Oliveira, Huawei Lin, Wen-Hai Zhang, Carlos Silvestre, Chi-Hou Chio, Junxiao Liu, Qiwei Chen, Hon-Pan Sio, Kam Weng Tam
{"title":"Microwave Displacement Sensing Based on Slot Antenna Over Metasurface and Its Applications for Automatic Trolling Motor","authors":"Paulo Olavo Lima Neves Oliveira, Huawei Lin, Wen-Hai Zhang, Carlos Silvestre, Chi-Hou Chio, Junxiao Liu, Qiwei Chen, Hon-Pan Sio, Kam Weng Tam","doi":"10.1049/ell2.70281","DOIUrl":"https://doi.org/10.1049/ell2.70281","url":null,"abstract":"<p>This letter presents a microwave displacement sensor based on a slot antenna integrated with a solar panel metasurface. By leveraging near-field coupling between the antenna and metasurface, the sensor achieves dual-band operation (<i>f<sub>1</sub></i> = 1.59 GHz/<i>f<sub>2</sub></i> = 2.37 GHz) with high sensitivity, enabling non-contact monitoring of distance, orientation, inclination, and obstructions. The solar panel in the trolling motor's power unit acts as a metasurface at microwave frequency. Its coupling with the control unit's antenna installed above the solar panel senses the antenna displacement that is in synchronous movement with the motor. Experiments reveal distinct displacement sensitivities (−5.0 MHz/mm for f₁, −9.0 MHz/mm for <i>f₂</i>) and quasi-linear orientation responses (2.11 MHz/° for <i>f₂</i>). Frequency shifts under rotation (70 MHz for f₁, 190 MHz for <i>f₂</i>) and inclination (5.0 MHz/° for <i>f₁</i>) demonstrate robust multi-axis detection, while obstruction tests highlight resilience in dynamic environments. Based on these dual frequency matching changes, a sensing approach is validated conducive as to anti-interference attitude estimation of the trolling motors’ automatic operation, addressing the need for durable, humidity-resilient, high-precision sensing in aquatic applications.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70281","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143909099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A New Design of High Power Gysel Power Divider/Combiner","authors":"Youna Jang, Minseong Kim, Dal Ahn","doi":"10.1049/ell2.70279","DOIUrl":"https://doi.org/10.1049/ell2.70279","url":null,"abstract":"<p>The conventional Gysel power divider/combiner uses two shunt resistors to facilitate heat dissipation. Heat sinks are essential for high-power dividers, to prevent high-power signals from damaging high-power resistors and to maintain the power that high power resistors are capable of handling. However, adding a heat sink to a power divider/combiner design using two resistors will increase the total volume of the power divider/combiner. To solve this problem, we have designed and developed a high-power divider/combiner of 0.5 kW that uses a single series resistor. The Gysel power divider is modified to design the high-power power divider, and a de-embedding method was applied to extract the Device Under Test (DUT) of the two-port high-power resistor to accurately implement line compensation, achieving magnitude balance within 0.16 dB.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70279","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143900908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marta Laguna, Esteban Marsal, Francisco Colodro Ruiz, Juana María Martínez Heredia, Manuel R. Arahal
{"title":"Time Interleaving in the Analogue Circuitry of Oversampled Digital-to-Analogue Converters: Proof of Concept","authors":"Marta Laguna, Esteban Marsal, Francisco Colodro Ruiz, Juana María Martínez Heredia, Manuel R. Arahal","doi":"10.1049/ell2.70280","DOIUrl":"https://doi.org/10.1049/ell2.70280","url":null,"abstract":"<p>Digital-to-analog converters (DACs) based on sigma-delta modulation are implemented with analog components that have low accuracy requirements. As a result, they have been widely employed in high-frequency transmitter architectures over the past decades. Time interleaving techniques allow parallel structures to operate at reduced speeds, thereby mitigating speed limitations in digital circuits. However, a common approach involves multiplexing the outputs of these parallel structures to reconstruct a single digital signal, which is subsequently converted to an analog voltage using a high-speed, low-resolution DAC. This work investigates the feasibility of employing a parallel array of low-speed DACs instead. To compensate for mismatches in analog paths, a novel dynamic element matching technique is proposed. Experimental results demonstrate that the proposed approach exhibits the characteristics required for high-frequency transmitter applications.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70280","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143900907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Adaptive Moving Target Detection for Forward Scatter Radar When the Noise Power Mismatch Occurs","authors":"Xiang Li, Zeyu Wang","doi":"10.1049/ell2.70276","DOIUrl":"https://doi.org/10.1049/ell2.70276","url":null,"abstract":"<p>This letter addresses the problem of detecting moving targets with forward scatter radar (FSR) when the noise power mismatch between the data under test (DUT) and the secondary data occurs. To model such mismatch, it is assumed that the noise power in the DUT and the noise power in the secondary data differ by a noise-scaling factor. Under both known and unknown noise power of the DUT, two kinds of adaptive moving target detectors for FSR are designed. The performance evaluation indicates that the proposed detectors have better detection performance than their counterparts, especially when the noise-scaling factor is large.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70276","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Design of Integrated Waveform for Detection and Cover Based on Maximum Value Constraint","authors":"Haoting Guo, Fulai Wang, Nanjun Li, Runlong Peng, Chen Pang, Yun Ren, Yongzhen Li","doi":"10.1049/ell2.70274","DOIUrl":"https://doi.org/10.1049/ell2.70274","url":null,"abstract":"<p>With the complexity of the electromagnetic environment, multi-function radar is emerging as a major development trend. To achieve multiple functions simultaneously, integrated waveform design has become a key technology in this field. In this letter, a method for designing integrated waveform with good autocorrelation and cover properties is proposed. A gradient-based nonlinear programming solver is implemented to solve the nonconvex optimization problem. Numerical results show that the peak sidelobe level (PSL) of the integrated waveform is lower than that of the conventional linear frequency modulation signal. Additionally, the waveform generates strong false targets with multiple controllable positions for non-cooperative radars. Besides, this letter describes the implementation of the proposed integrated waveforms on hardware and corroborates their performance through experimental results.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70274","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}