In this research, the optimization of antenna parameters for the Vivaldi antenna, Inverted F antenna, and Probe Feed Microstrip Patch antenna was carried out using EOLRKC and the Sugeno Fuzzy Inference System (SFIS) machine learning techniques. The research explores numerical and conventional antenna design methods to understand the necessary concepts comprehensively. After a thorough analysis, an intelligent model for antenna selection recommends the best antenna based on various performance metrics evaluated with the Enhanced Logistic Regression Kernel Classifier. Additionally, the geometric properties of the antenna are discussed, and the SFIS is developed by integrating five primary learners to maximize the potential of each learner type. The EOLRK Classifier classifies antennas into three groups: Vivaldi, Inverted F, and Probe Feed Microstrip Patch, while SFIS determines the optimal parameters for antenna size. The accuracy of the EOLRK Classifier is assessed, while the performance of the Sugeno FIS is evaluated using MSE and MAPE. The proposed methodology achieves a MAPE below 4% and an accuracy exceeding 99%, demonstrating exceptional performance in parameter prediction and antenna classification. Implementing these methods has the potential to enhance innovative antenna design practices significantly.

A compact ultra-wideband antenna fed by coplanar waveguide is reported in this paper. The designed antenna consists of a trumpet-shaped planar radiation patch and a symmetrical ground patch. Two Mickey-Mouse shaped perturbative slots and two quarter-elliptical grooves are etched on the ground to obtain better impedance matching. By prolonging the radiation patch, a very wide −10 dB bandwidth of covering 300 MHz-18 GHz with bandwidth ratio up to 60:1 and omnidirectional coverage are achieved. Furthermore, the proposed antenna is able to cover P(0.3-1G), L(1-2G), S(2-4G), C(4-8G), X(8-12G), and Ku (12-18G) bands, which is much preferred for wideband spectrum monitoring.

This paper proposes a method to calculate temperature distribution by analyzing periodic units, enabling efficient simulation of electromagnetic-thermal problems in periodic structures. Compared with traditional methods that require high memory and long computation times to process the entire large-scale model, this approach significantly reduces computational complexity by focusing on a single periodic unit and incorporating periodic thermal boundary conditions. In the study, electromagnetic losses are considered as the heat source, and the formula for periodic thermal boundary conditions is derived in conjunction with the heat conduction equation, achieving the integration of periodic electromagnetic-thermal boundary conditions. Numerical validation and comparison with global model results demonstrate that the proposed method maintains accuracy while achieving high efficiency. Furthermore, the method is applied to an artificial magnetic conductor (AMC) model, with calculation results closely matching those of large-scale unit arrays, further verifying the correctness and applicability of the algorithm.

Work mode boundary detection can provide basic information units for the recognition of consecutive work modes in the intercepted multi-function radar (MFR) pulse sequence. The existing boundary detection methods tend to detect false boundaries when the pulse parameters vary drastically within the work mode, such as when the pulse repetition interval (PRI) modulation type is stagger or agile. To address the issue of over-detection of the work mode transition boundary, a new work mode boundary detection method is proposed based on the arc crossings (AC). It utilizes the AC to quantify and annotate the similarities within MFR work modes. Without relying on prior knowledge, it can accurately capture the structural characteristics of the boundary transition and effectively adapt to different pulse parameter modulation types. The experimental results show that it reduces the segmentation probabilistic error by 8.7% and the false alarm rate by 19.85% compared to the baseline algorithm.

This paper presents the design, fabrication, and characterization of a novel 3D-printed helical antenna operating within the 9.4-10.8 GHz frequency band. The antenna, employing a lightweight paper substrate and a strip-based helical structure, exhibits robust circular polarization characteristics and wideband operation. Rigorous simulations predict a peak CP gain of 11.7 dBi at 9.8 GHz and a high simulated radiation efficiency of 95%. Experimental measurements validate these predictions, achieving a peak CP gain of 11.6 dBi at 9.8 GHz. This research demonstrates the potential of 3D-printed helical antennas for diverse applications in modern wireless communication systems, including 5G, satellite communication, and radar. Furthermore, this study leverages the power of Artificial Intelligence (AI) by employing the Grey Wolf Optimizer (GWO), a sophisticated metaheuristic algorithm, to optimize the antenna's design. The GWO algorithm is utilized to efficiently search the design space and identify optimal values for key parameters, such as the number of turns, helix pitch, and helix diameter, with the objective of maximizing antenna gain to achieve a target of 15 dBi. This research highlights the potential of AI-driven optimization techniques in advancing the design of high-performance antennas for emerging wireless communication systems.

Aiming at the issues of drive signal errors and high computational complexity in conventional model predictive control, a virtual vector modulation-based model predictive control (DSO-VVMMPC) strategy with drive signal optimization for quasi-Z-source inverter-fed permanent magnet synchronous motor (QZSI-PMSM) system is proposed in this paper. In the proposed strategy, the drive pulses are generated by the combined effect of straight-through voltage vectors (ST VVs) and non-straight-through (NST) VVs over one control period to reduce the ripples of inductor current and stator current. Firstly, the accurate drive signals can be obtained by applying deadbeat algorithm to calculate and correct. The judgment of which sector the reference voltage vector is in and the construction of a cost function for finding the optimal objective are not required. Thus, the computational burden of control system is reduced significantly. In addition, the drive signals are optimized to output to reduce the effect of minimum pulse width on the accuracy of deadbeat algorithm. The steady-state performance of proposed strategy is further improved. Finally, the feasibility and effectiveness of proposed strategy are confirmed by conducting comparative experiments on the RT-LAB experimental platform.

This paper proposes a high gain wide band stacked antenna using multiple meta-surfaces that offers stable radiation patterns with low cross-polarization level (CPL) and side-lobe level (SLL) for 5G applications. The suspended microstrip antenna (SMSA) offers high gain and wide bandwidth but the radiations from probe feed cause high CPL. SMSA design with meta-surfaces increases the inductive impedance of SMSA, therefore, the substrate height is decreased to increase the capacitance to compensate this inductive impedance. It decreases the cross-polar radiation due to decrease in probe feed length. Meta-surfaces electromagnetically couple with SMSA and enhance the bandwidth of antenna. SMSA with meta-surfaces is placed in a half-wavelength Fabry Perot Cavity (FPC) to enhance the gain of antenna. The proposed antenna offers S₁₁ < -10 dB, peak gain of 16.4 dBi, SLL < -23 dB and CPL < -23 dB and front to back lobe ratio (FBR) > 22 dB over 3.3-3.9 GHz. The structure is fabricated and tested. The measured results are close to the simulation ones. The proposed structure based on its radiation characteristics is a suitable candidate for 5G applications.

Alzheimer's disease (AD) is a brain degenerative disease, so the Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET) of cerebral images are effective data in detecting the onset of the disease. In this work, a framework consisting of a cross attention multimodal fusion deep neural network and a patches weight optimization strategy is proposed. First, multiple points are randomly selected from the region of interest (ROI), and multiple 3-axial-plane patches are extracted centered on these points. Then, the patches from MRI and PET are fused using a fusion neural network to output diagnostic information for each patch. Finally, a weight is set for each patch; a particle swarm optimization algorithm is used to find the optimal weights for multiple patches; the diagnostic information from multiple patches is merged using these weights; and the final diagnostic results are output. The experiments on ADNI dataset show that this method has an accuracy of 94.03% in diagnosing AD and outperforms other methods of fusing MRI and PET data, which demonstrates the promising performance of this method.

Double-Sided Flux Switching Permanent Magnet Linear (DLFSPM) motors are characterized by high efficiency and high power density, which are more and more widely used in various fields, so the design of high-performance linear flux-switching PM motors is of great significance to improving the efficiency of industrial applications. This study aims to achieve the improvement of electromagnetic thrust of double-sided flux switching permanent magnet linear motor by optimizing the motor core structure. First, a theoretical approach is used to construct the motor model and derive the electromagnetic thrust equation. Second, the finite element and Bessel curve fitting methods are used to optimize the core structure to enhance the electromagnetic thrust. Subsequently, the conductive bridge structure is increased to reduce the detent force and improve the performance. Then, the modular structure of primary iron core unit is proposed based on the above two optimizations. Finally, finite element simulation of the proposed optimized structure is carried out to compare the electromagnetic performance of the final comprehensively optimized DLFSPM motor with that of the motor of the initial structure. It is found that the average electromagnetic thrust is increased by 57.85%, and the amplitude of the detent force is reduced by 48.34%, which verifies the effectiveness of the optimization method.

This article introduces a Circularly-Polarized (CP) inverted cup-shaped Hybrid Cylindrical-Dielectric-Resonator-Antenna (HCDRA) combined with an asymmetric Jerusalem cross unit-cell based metasurface (MTS). The antenna, designed for use in the 5G n-79 NR band (4400-5000 MHz) and IEEE 802.11n-WLAN (5 GHz) applications, features a unique disturbed coax-feed mechanism at the edge of cylindrical DR and an asymmetric MTS that boosts the circular polarization within the DR antenna. The antenna's E-field and parametric analysis provide evidence of CP radiation. The proposed HCDRA achieves impressive S₁₁ and Axial-Ratio (AR) bandwidths of 2.1 GHz and 740 MHz, with a maximum gain of 6.825 dBic. The overall gain obtained is consistently more than 5.5 dBic across the entire bandwidth of the HCDRA. The fabricated HCDRA is tested in an anechoic chamber, and the obtained practical results closely matched the simulation outcomes, confirming the performance of the proposed design.

The paper describes a two-layer low-profile antenna design suitable for sub-6 GHz communications that operates at 5.8 GHz. The proposed antenna is integrated with a periodic plus-shaped EBG structure to obtain gain and bandwidth enhancement. The realized gains of the prototype with and without periodic structure are 3.48 dBi and 2.4 dBi, respectively. Additionally, it is observed that the measured bandwidth of the antenna structure at 5.75 GHz with periodic structure is 230 MHz, while without periodic structure it is 150 MHz, which accounts for 35% bandwidth enhancement. The simulated and measured results validate that the proposed compact antenna prototype is a suitable candidate for sub-6 GHz application in the 5G spectrum.

This article introduces a quad-port Multiple Input Multiple Output (MIMO) staircase U-shaped wideband antenna for a 5G New Radio (NR) wireless. The miniaturization of the configuration is achieved with a staircase U-shaped radiating element, and an I-shaped stub etched with rectangular strips between radiating elements provides enhanced isolation. The measured bandwidth of 4.5 GHz is obtained with an isolation, radiation efficiency, and gain above 17 dB, 80%, and 6.5 dB respectively. Certain parameters, such as envelope correlation coefficient (ECC), diversity gain (DG), mean effective gain (MEG), channel capacity loss (CCL), and total active reflection coefficient (TARC), are also evaluated to ensure that the designed MIMO system adheres to its requirements. Hence, the suggested antenna suits the 5G New Radio applications.

The paper presents array-pattern synthesis for wide-band nulling at specified directions. The projection matrix method is invoked to obtain an orthogonal operator matrix (OOM). The OOM transforms a quiescent excitation vector to an optimally modified excitation vector that warrants ideal nulls at the desired directions at multiple frequencies. However, the modified excitation does not provide the optimal solution for a shaped beam, particularly near the edge-of-coverage region. We obtain an improved shaped beam solution by determining a complete set of orthonormal basis vectors that represent the column space of the OOM. Optimum amplitudes of the basis vectors yield an improved shaped beam. The method is amended for nulls in phased array-fed reflector (PAFR) antenna patterns. The method does not require explicit determination of eigenvalues and eigenvectors, thereby enhancing the computation efficiency facilitating easy implementation in a digital processor. As a consequence, real time nulling in phased arrays and PAFRs are feasible with minimal computation burden, appealing to communication satellites.

This work proposes a compact multiband Symmetrically Stepped Phase Cancellation Reflective Surface (PCRS) that can be used to lower radar cross section (RCS), achieve high Absorption Conversion Ratio (ACR) and high Polarization Conversion Ratio (PCR). Two FR4 layers make up the Symmetrically Stepped PCRS unit cell. With three asymmetrically positioned vias along its diagonal, the Symmetrically Stepped patch is present in the first FR4 layer, which has a thickness (t1) of 1.6 mm and high PCR and ACR. On top of layer 1, there is another layer of FR4 stacked with a thickness (t2) of 3.2 mm to give multiple bands with improved bandwidth efficiency. The PCRS unit cell's entire dimensions, which are only 5 mm x 5 mm x 4.8 mm, are determined by its lowest operational wavelength. Multiple frequencies, 5.6 GHz, 9.8 GHz, 11.3 GHz, and 16.7 GHz, yield RCS reductions of 24 dB, 33 dB, 42 dB, and 24 dB, respectively. 99.9% maximum PCR and 99.9% maximum ACR are obtained with up to 60 degrees of angular stability. Furthermore, in order to minimize RCS and prevent unnecessary reflections from the PCRS, the proposed reflective PCRS unit cells are positioned orthogonally to offer reflection phase cancellation. The most important objective of the proposed research is to lower the RCS while maintaining high PCR and ACR in various frequency bands that are necessary for detection and stealth technologies.

Aiming at the operation stability of transformer with harmonic invasion in offshore wind farm, the evolution and propagation of electromagnetic-solid-acoustic information are studied. Combined with the measured data of invasive harmonic currents, it is found that the proportions of the 5th and 7th harmonics are larger than those of other harmonics. A multi-physical field propagation and information extraction method for transformer is proposed based on the principle of electromagnetic-solid-acoustic coupling. Then, the magnetic density, force, vibration, and noise characteristics of components with harmonic invasion are analyzed. The results show that the increase of harmonics intensifies the vibration and noise of transformer in the same load. In the same harmonic proportion, the waveform distortion of the multi-physical characteristic parameters caused by the 7th harmonic is more significant than the 5th. Moreover, the vibration and noise intensify with rising load factor in the same harmonic invasion mode. Meanwhile, the dynamic experimental platforms are built to measure multi-physics field information in different modes. By comparing the experimental data and simulation result, the accuracy of proposed method can be verified. Furthermore, the 5th harmonic is selected as the typical characterization parameter to study the mapping relationship between harmonics and vibration characteristics. The criteria for disturbed destabilization are formulated, providing new ideas for the life cycle operation and maintenance of offshore wind transformer.

This work, for the first time to our knowledge, describes in detail the incorporation of the numerical and semi-analytical intelligent reflector scattering models into the modelling framework of the state-of-art dual-polarization three-dimensional geometrical channel models, where propagation channel impact and antennas impact are separated. The proposed formalism allows indoor coverage impact studies of the meta reflectors in mmWave and THz radio communication systems. The model considers reflector phase-design, near-field effects, polarization transformations, incident beam patterns, multipath and diffraction effects, and is confirmed by full-wave simulations and measurements.

In this work, we propose a technique to enhance the performance of circular patch antennas using an embedded system of cylindrical impedance surfaces. The technique utilizes a derived analytical model of a circular patch antenna containing an arbitrary number of coaxial impedance surfaces along with nonlinear optimization algorithms. This allows for the calculation of the radius and impedance of each surface to achieve the desired matching frequency band for given antenna dimensions. We demonstrate two applications of adding an optimal set of impedance surfaces into a compact circular patch antenna, i.e., the expansion of the matching frequency band keeping constant antenna dimensions and the miniaturization (height reduction) maintaining the constant bandwidth. Two corresponding versions of a cavity-backed circular patch antenna each having three impedance surfaces are synthesized. Practical implementations for both versions are designed and considered in full-wave numerical verification of analytically predicted properties. A comparison with the conventional method using multi-element microstrip matching circuits shows a benefit in radiation efficiency.

In this paper, an optimized flexible Microstrip Patch Antenna (MPA) for wearable applications is introduced, particularly characterized by its design concepts of scalable design and comprehensive performance evaluation. The proposed antenna leverages the mechanical flexibility of a leather substrate, complemented by polyimide layers on the upper and lower surfaces of the copper patch, enhancing both structural integrity and electromagnetic performance. The design is optimized for the operation at 2.4\,GHz, ensuring durability and stability even under dynamic bending conditions. Various critical performance metrics, such as resonance frequency, bandwidth, return loss, Voltage Standing Wave Ratio (VSWR), Specific Absorption Rate (SAR) and gain, are evaluated experimentally and through simulation across bending angles of 0-90°. Results also show that the antenna can reliably operate in an extreme bending scenario while having a resonant frequency near 2.44 GHz with a return loss (S₁₁) less than -20 dB up to 60° bending. At approximately 31 MHz bandwidth stability is preserved, and the VSWR is less than 1.2, thus the impedance matching is effective. Further gain measurements are also made under deformation, which further confirms the stable performance and thus reliability of the wearable application. Additionally, SAR analysis is conducted to ensure the antenna's compliance with electromagnetic exposure safety limits. The maximum SAR value of 0.516 W/kg remains well within FCC (1.6 W/kg) and ICNIRP (2.0 W/kg) standards, confirming safe radiation levels. Polyimide shielding improves durability, reduces interference, and minimizes backward radiation, making the design ideal for Wireless Body Area Networks (WBANs) and biomedical monitoring.

In order to solve the problems of susceptibility to environmental disturbances, complex installation and low reliability caused by the photoelectric code disks in the permanent magnet assisted bearingless synchronous reluctance motor (PMa-BSynRM) system, an improved BP neural network (BPNN) left-inverse system is proposed to establish the speed self-sensing system of the PMa-BSynRM. Firstly, the mathematical model of the PMa-BSynRM is established, and the left reversibility of the PMa-BSynRM speed subsystem is analyzed. Secondly, the traditional BP neural network is optimized from four aspects, including the number of neurons in the hidden layer, initial weight, connection weight and learning rate. Then, the improved BPNN model is used as the inverse model of the left inverse system to fit the speed subsystem of the PMa-BSynRM. Finally, the simulation results show that accurate estimation of the speed and rotor position is achieved by the proposed speed self-detection system, and the accuracy and feasibility of the proposed speed self-detection system are validated by the experimental results.

This paper describes the low sidelobe pattern synthesis of planar arrays having a distorted triangular or rectangular lattice. This distortion concerns variable row displacements applied to a triangular, skew or rectangular element lattice. The applied low sidelobe pattern synthesis is based on the iterative Fourier transform (IFT) method that makes extensive use of forward and inverse FFTs. Recently this author has developed new forward and inverse 2D FFT formulations. Due to these two new FFT formulations, the application of the IFT method is no longer limited to the pattern synthesis of a planar array having a rectangular lattice but can now also be applied to array apertures with a triangular or skew element lattice and even when such lattice has displaced element rows. The new IFT method is employed in this paper for the low sidelobe pattern synthesis of arrays featuring displaced element rows. The presented synthesized pattern results, which refer to the sum pattern, concern three planar arrays each with displaced element rows applied to a square or triangular lattice. The sum pattern of the considered antennas has to meet peak sidelobe level (PSLL) requirements for two nulling ring sectors, one of ≤-50 dB and the other of ≤-68 dB. The sum pattern of the third example includes a rectangular nulling sector specified by a PSLL of <– 80 dB.