Latest ArticlesTo address the issues of insufficient low-frequency coverage and oversized antennas in radio monitoring systems,a miniaturized ultra-wideband receiving antenna based on improved dipole structure is proposed. The design employs meandering techniques to bend the dipole arms (dimensions: 38.6 mm×134.1 mm×0.8 mm),integrating symmetrical parasitic elements and slotted structures to optimize current distribution and extend bandwidth. CST simulations and measurements demonstrate that the antenna achieves S11<-6 dB across 0.7~0.96 GHz and 1.3~5.3 GHz bands,covering standards such as GSM,DCS-1800,WLAN,WiMAX,and 5G NR n77/n78/n79.The radiation efficiency reaches 96.42% at 2.2 GHz and 95.63% at 4.4 GHz,with 85.4%±6.8% average efficiency in 5G Sub-6 GHz bands. The maximum gain of ( 4.23±0.54) dBi ( 3.3~5.0 GHz) surpasses conventional dipoles by 1.8 dBi. This structural innovation resolves the low-frequency coverage vs miniaturization trade-off,enabling multi-standard communication monitoring.
A dual band dual circularly polarized symmetric array antenna component is proposed to address the issue of independent receiving and transmitting antennas in traditional TT&C fields. A symmetrical array antenna is adopted to achieve dual band operation characteristics, while a 3 dB bridge is used to realize dual circularly polarized radiation characteristics, and a duplexer is stacked below the antenna to achieve high isolation between the receiving and transmitting frequency bands. Based on this design concept, an antenna prototype is manufactured and tested based on the simulation analysis. The results show that the designed antenna can operate in frequency bands covering 1.75~1.85 GHz and 2.2~2.4 GHz, and the axial ratio within these bands is less than 3 dB. The suppression between the receiving channel and the transmitting channel reaches over 70 dB. This provides a feasible design scheme for the shared antenna unit for transmitting and receiving in practical engineering.
A wideband radial power combiner based on Ridge Gap Waveguide ( RGW) is designed for high-power combining applications in the wide millimeter-wave frequency band. The combiner consists of two metallic plates, with the center of the lower plate fed by a coaxial line. The energy is reflected by multiple metallic conical structures positioned above the plate, and directed into the radial transmission lines, achieving equal power division. The radial transmission lines employ ridge gap waveguides, which is built up by placing pin-type Electromagnetic Band-Gap (EBG) structures on the metal bottom plates adjacent to the ridge, effectively reducing coupling among adjacent channels without the need for welding the upper and lower plates. Simulation results show that the combiner operates within the frequency range from 14.7 to 37.5 GHz, with a reflection coefficient of less than -15 dB and a transmission coefficient of approximately -6.1 dB. The measurement results show good agreement with the simulation results.
Vision-Language-Action (VLA) models are a core technology for achieving general embodied artificial intelligence, aiming to integrate visual perception, language understanding, and action decision-making within a unified end-to-end framework. The current research status and development trajectory of VLA models are comprehensively and systematically reviewed. The theoretical origins of VLA models are traced, and the paradigm shift from modular designs to unified architectures is clarified. Along the evolutionary path of VLA, representative works such as SpatialVLA, TLA, and GR00T N1 are presented with a focus on multimodal fusion and cognitive hierarchies. A detailed taxonomy of VLA models is constructed from two key dimensions-macro architecture and system hierarchy. Key technologies and design principles are deeply analyzed, ranging from pioneering works such as RT-1, to models introducing large-scale knowledge transfer such as RT-2, OpenVLA, and ECOT, and further to cutting-edge dual-system architectures such as Helix, OpenHelix, DexVLA, and DexGraspVLA. Mainstream simulation environments, core datasets, and benchmarks supporting VLA research are systematically integrated and reviewed. The application status and prospects of VLA models in robotic manipulation, autonomous navigation, and industrial automation are explored. Core challenges in current VLA research are analyzed, including generalization and data efficiency, long-horizon task planning, and real-time responsiveness. Future research directions are discussed, including integration with world models and enhancement of data efficiency.
The rising incidence of skin lesions has made early screening for skin cancer increasingly critical. However, existing methods for skin lesion image segmentation often suffer from limitations in channel-wise information modeling, structural adaptability, and feature fusion, which can lead to inaccurate boundary delineation and insufficient utilization of crucial contextual information. To address these issues, a skin lesions image segmentation method based on attention mechanism and wavelet transform, termed AW-SkinNet, is proposed. The proposed approach employs a dual-branch collaborative attention module to extract spatial and channel-dependent features, integrates wavelet transform to enhance frequency-domain representations, and incorporates lightweight attention-guided sub-pixel upsampling to improve detail restoration and contextual understanding. Experimental results on the ISIC-2017 and ISIC-2018 skin lesion segmentation datasets demonstrate that the proposed method achieves higher segmentation accuracy compared with existing approaches for skin lesion image segmentation.
To solve the problems of tracking and positioning of airborne early warning aircraft and other long-range targets,a high-precision passive positioning strategy based on the collaborative networking of UAVs and passive radar is proposed. By analyzing the impact of the layout of multi-station passive radar on positioning accuracy,a layout strategy that can improve positioning accuracy and reduce layout costs is designed. Time Difference of Arrival (TDOA) positioning method is applied in the study,and on this basis,the Geometric Dilution of Precision ( GDOP) for multiple stations is analyzed to evaluate the impact of the layout form on positioning accuracy. A collaborative strategy is proposed that,when the initial direction of the target is unknown,first uses a star-shaped layout for initial positioning and then switches to an inverted triangular layout for high-precision secondary positioning. The optimal secondary stations are selected using the “virtual structure method”and the flight trajectory of the UAV is optimized using an improved Particle Swarm Optimization ( PSO) algorithm to achieve high-precision layout. Simulation results show that this strategy can significantly improve positioning accuracy. Compared with traditional passive radar systems,positioning error is significantly reduced,and system response speed is faster. The research results have certain application value in practice.
The application value of Brain-Computer Interface (BCI) and human-machine integration technology in the fields of UAV control and countermeasure equipment operation is explored, the problems faced by these technologies are analyzed, and targeted solutions are proposed to promote their rational application in the development of the low-altitude economy and security protection. By analyzing the role of BCI technology in improving UAV control efficiency and enhancing the accuracy of countermeasure equipment operation, and combining the new application scenarios that BCI technology shapes for the low-altitude economy and the new form of low-altitude security protection it creates, the problems faced by these technologies are sorted out, such as inherent defects of human-machine integration technology, information security risks, and their impacts on low-altitude security, and corresponding countermeasures are further put forward. BCI technology plays a significant role in the fields of UAV control and countermeasure equipment operation: it can improve UAV control efficiency and enhance the accuracy of countermeasure equipment operation. Based on BCI and human-machine integration technology, new application scenarios for the low-altitude economy have been shaped, and a new form of low-altitude security protection has been created.
To solve the problem of stable information transmission for unmanned systems in complex electromagnetic environments, the information elastic adaptation method for unmanned systems based on communication quality assessment is proposed. Signal strength, bit error rate, and signal-to-noise ratio at the communication link layer are selected as characteristic parameters for communication quality assessment. Long Short-Term Memory ( LSTM) network is served as the signal prediction model to estimate future signal parameters, while a Support Vector Regression (SVR) model is employed to evaluate real-time communication quality. Based on the communication quality level evaluation model, the communication quality evaluation results are obtained; corresponding level of content is transmitted according to the communication quality level. Simulations using real-world data and field tests demonstrate that the proposed method ensures reliable information transmission for unmanned systems in highly dynamic and contested electromagnetic environments.
To address the communication technology requirements for online monitoring and digital operation & maintenance of high-voltage transmission lines, as well as the shortcomings of existing communication methods such as optical fiber, 4G/5G in terms of adaptability to complex environments, coverage integrity, and cost control, the characteristics and requirements of current communication methods for high-voltage transmission lines are analyzed. Relying on a National Key Research and Development Plan project, a solution for a highly reliable broadband ultra-multi-hop wireless ad hoc network communication system is studied and proposed, which overcomes the technical issue of a sharp decline in quality of service after multi-hop wireless transmission, and a secure broadband ultra-multi-hop wireless ad hoc network communication system is constructed, realizing long-distance broadband service transmission with Quality of Service(QoS) assurance. The constructed ultra-multi-hop wireless ad hoc network communication system is simulated and tested though the OMNeT++ simulation platform, 9-node outdoor field tests, and on-site operation in the 220 kV Binxing First Line of State Grid Tianjin. The simulation and test results show that the system can achieve 50-hop broadband wireless data transmission with an end-to-end traffic of no less than 2 Mb/s. Compared with traditional technical route, this system features stronger technical adaptability and lower operation and maintenance costs. It enhances the digital operation and maintenance level of power grids and provides a reliable solution for the construction of communication networks in new-type power systems.
To address the inadequacy of multimodal data fusion and complexities in dynamic constraint optimization for satellite mission requirement decision-making, an intelligent decision model is designed to enhance automation and accuracy. The proposed Retrieval-Augmented Generation (RAG)-based optimization model for satellite mission planning comprises: ① An input layer receiving multimodal data such as user requirement texts and geospatial coordinates, etc. ; ② A processing layer integrating Transformer-architecture Large Language Model ( LLM) with vector databases to enable semantic retrieval and knowledge augmentation; ③ A constraint verification module in the output layer generating feasible solutions; ④ A feedback layer dynamically updating the knowledge base. Experimental validation demonstrates 90% decision accuracy—achieving 20% and 9.8% absolute accuracy improvements over conventional Rule-Based Expert Systems ( RBES) and Machine Learning Models ( MLM ), respectively. The model significantly enhances adaptability in satellite mission decision-making, enables efficient resource allocation under dynamic constraints, and exhibits substantial engineering applicability.