PIER C | PIER Journals

2025-03-15

PIER C

Vol. 153, 225-232, 2025

doi:10.2528/PIERC25011904

download: 17

A Compact Ultra-Wideband Microstrip Antenna for Spectrum Monitoring

Yu Liu, Shuo Yu and Xiaoming Liu

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.

A Compact Ultra-Wideband Microstrip Antenna for Spectrum Monitoring

2025-03-14

PIER C

Vol. 153, 219-224, 2025

doi:10.2528/PIERC24121503

download: 15

Efficient Electro-Thermal Analysis of Periodic Artificial Magnetic Conductors (AMC)

Zhonghui Li, Minquan Li, Xian-Liang Wu, Shuangqing Cao and Rongxian Bai

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.

Efficient Electro-thermal Analysis of Periodic Artificial Magnetic Conductors (AMC)

2025-03-14

PIER C

Vol. 153, 213-218, 2025

doi:10.2528/PIERC24123101

download: 11

A Novel Method for Multi-Function Radar Work Mode Boundary Detection

Yuxin Fu, Jiantao Wang, Jie Huang, Tongxin Dang and Yiming Li

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.

A Novel Method for Multi-function Radar Work Mode Boundary Detection

2025-03-13

PIER C

Vol. 153, 201-211, 2025

doi:10.2528/PIERC25011305

download: 23

Advanced Helical Antenna Design for X-Band Applications Using AI

Mohammed Yousif Zeain, Maisarah Abu, Apriana Toding, Zahriladha Zakaria, Hussein Alsariera, Ihsan Ullah, Ali Abdulateef Abdulbari, Hamizan Yon, Bilal Salman Taha and Muhammad Inam Abbasi

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.

2025-03-13

PIER C

Vol. 153, 189-200, 2025

doi:10.2528/PIERC25012505

download: 28

Virtual Vector Modulation-Based Model Predictive Control Strategy with Drive Signal Optimization for Quasi-Z-Source Inverter-Fed Permanent Magnet Synchronous Motor System

Yang Zhang, Kun Cao, Yang Gao, Ping Yang, Xingwang Chen and Zhun Cheng

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.

Virtual Vector Modulation-based Model Predictive Control Strategy with Drive Signal Optimization for Quasi-Z-Source Inverter-fed Permanent Magnet Synchronous Motor System

2025-03-12

PIER C

Vol. 153, 179-188, 2025

doi:10.2528/PIERC25010101

download: 20

Meta-Surfaces Based High Gain Wide-Band Stacked Antenna with Low Cross-Polarization and Side Lobe Level for 5G Applications

Anjali Rochkari, Vijaypal Yadav, Mahadu Annarao Trimukhe, Nayana Chaskar, Meenakshi Awasthi and Rajiv Kumar Gupta

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.

Meta-surfaces Based High Gain Wide-band Stacked Antenna with Low Cross-polarization and Side Lobe Level for 5G Applications

2025-03-12

PIER C

Vol. 153, 169-177, 2025

doi:10.2528/PIERC25012203

download: 20

Diagnosing Alzheimer's Disease Using Multimodal Fusion Neural Network and Weight Optimization for 3-Axial-Plane Patches of MRI and PET

Weiming Lin, Shumin Feng, Hongfeng Wu and Jinlin Ma

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.

Diagnosing Alzheimer's Disease Using Multimodal Fusion Neural Network and Weight Optimization for 3-axial-plane Patches of MRI and PET

2025-03-12

PIER C

Vol. 153, 159-168, 2025

doi:10.2528/PIERC25011505

download: 25

Optimization of Electromagnetic Thrust for Double-Sided Flux Switching Permanent Magnet Linear Motor

Cheng Wen, Aosai Li, Mingye Li, Wei Du, Shiming Bai and Xiangyu Meng

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.

Optimization of Electromagnetic Thrust for Double-sided Flux Switching Permanent Magnet Linear Motor

2025-03-11

PIER C

Vol. 153, 149-157, 2025

doi:10.2528/PIERC25012001

download: 23

Wide-Band Pattern Nulling in Phased Array and Phased Array-Fed Reflector Antennas

Arun K. Bhattacharyya

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.

Wide-band Pattern Nulling in Phased Array and Phased Array-fed Reflector Antennas

2025-03-06

PIER C

Vol. 153, 141-148, 2025

doi:10.2528/PIERC25010706

download: 55

Design and Performance Evaluation of a Flexible Microstrip Patch Antenna with Polyimide Protection for Wearable Applications

S. Sadhish Prabhu and Chandrapragasam Tharini

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.

2025-03-06

PIER C

Vol. 153, 129-140, 2025

doi:10.2528/PIERC25010703

download: 44

Speed Sensorless Control of Magnet Assisted Bearingless Synchronous Reluctance Motor Based on Improved BP Neural Network

Chao Chen and Huangqiu Zhu

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.

Speed Sensorless Control of Magnet Assisted Bearingless Synchronous Reluctance Motor Based on Improved BP Neural Network

2025-03-04

PIER C

Vol. 153, 119-127, 2025

doi:10.2528/PIERC25011303

download: 46

A Miniaturized Circularly Polarized Microstrip Antenna Utilizing Meandering Technique and Minkowski-Sierpinski Fractal Structure

Lin Wang, Liang Zhang, Lixia Yang, Xinyan Wang, Xialin Sheng, Quan Jin and Po Tian

In this paper, we present a miniaturized design of a microstrip antenna achieved through the Combination of Minkowski-Sierpinski(M-S) fractal structure and meandering technique, enabling the antenna to be integrated into smaller systems. The antenna achieves right-hand circular polarization (RHCP) through chamfering on a square patch. Further miniaturization is accomplished by loading four symmetrically opposed L-shaped slots along with M-S fractal structure. Specifically, the Minkowski structure undergoes a single iteration, while the Sierpinski fractal is iterated twice on the once-iterated Minkowski fractal to optimize performance. The antenna is manufactured on a textile substrate TLX-8 with dimensions of 50 mm × 50 mm × 0.762 mm, representing a 54.3% reduction in size compared to traditional designs. Moreover, the substrate exhibits robust mechanical properties. Experimental results demonstrate that the antenna achieves excellent radiation characteristics within a bandwidth of 1.563 to 1.581 GHz, an axial ratio bandwidth of 1.569 to 1.578 GHz. These performance metrics meet the requirements for modern Global Positioning System (GPS) antenna applications, highlighting the design's suitability for advanced integration in contemporary electronic systems.

A Miniaturized Circularly Polarized Microstrip Antenna Utilizing Meandering Technique and Minkowski-Sierpinski Fractal Structure

2025-03-03

PIER C

Vol. 153, 105-117, 2025

doi:10.2528/PIERC25011502

download: 38

Improved Model Predictive Torque Control Strategy Incorporating Decoupled Sliding Mode Disturbance Observer for PMSM

Yang Zhang, Ping Yang, Kun Cao, Yang Gao, Gao Tang and Qing Chen

Aiming at the problems of adjusting the weighting factor, significant torque ripple, and insufficient robustness against load disturbances in conventional model predictive torque control (MPTC) for PMSM, an improved model predictive torque control (IMPTC) strategy incorporating a decoupled sliding mode disturbance observer (DSMDO) is proposed. Firstly, the cost function is divided into two components, and both of them are evaluated sequentially to eliminate the need for weighting factors. Secondly, the set of candidate voltage vectors (VVs) is expanded by the VVs modulation technique to reduce the torque ripple, and a low-complexity method is introduced to determine the sector. Subsequently, the action time of the optimal VV is further corrected, which enhances the control of flux while reducing computational complexity. Additionally, a novel sliding mode disturbance observer with decoupling capability is introduced, which offers feedforward compensation to the speed loop and improves system robustness against disturbances. Finally, the correctness and effectiveness of the proposed IMPTC strategy with DSMDO are proved by the experimental results.

Improved Model Predictive Torque Control Strategy Incorporating Decoupled Sliding Mode Disturbance Observer for PMSM

2025-03-03

PIER C

Vol. 153, 93-103, 2025

doi:10.2528/PIERC24112907

download: 42

Study on the Application of Improved Fuzzy Adaptive Control on PMSM System

Xuhong Yang, Chenhao Li, Sujie Zhang and Fengwei Qian

Aiming at the problem of low robustness of fuzzy adaptive control when it is applied to permanent magnet synchronous motor system (PMSM), the study introduced the sliding film control method to optimize it, so as to enhance the robustness of PMSM. The results demonstrated that the torque error of the adaptive fuzzy sliding mode control(AFSMC) was 1.86 Nm, which is 62.8% and 38% less than the peak torque pulsation of 5 Nm and 3 Nm for the fuzzy adaptive control, respectively, and indicates a better steady-state capability when the motor is operated at 1500 rpm and 30 Nm load. In addition, in the robustness validation experiments, under the initial stage, the two methods have the same rotational speed response, but after the parameter changes, the AFSMC adjusts quickly, while the traditional fuzzy adaptive control responds slowly. Moreover, under the same load inertia, the AFSMC exhibits smaller overshoot and faster regulation, smaller speed fluctuation and faster recovery during load surge. In complex scenarios, AFSMC reduces recovery time by 60% over traditional control methods, which demonstrates that the fuzzy adaptive sliding film control proposed by the study is successful in enhancing the system's stability and capability when the PMSM is applied.

Study on the Application of Improved Fuzzy Adaptive Control on PMSM System

2025-03-01

PIER C

Vol. 153, 87-92, 2025

doi:10.2528/PIERC25011304

download: 62

Yagi-Antenna Array Loaded with Multi-Layer Composite Decoupling Structure

Minjie Guo, Junkang Song, Xiaohei Yan, Haiyan Zeng, Xin Zheng, Xiumei Huang and Shanglin Xie

In this paper, a multi-layer decoupling metamaterial unit (ML-DMU) is proposed to reduce the mutual coupling in a Yagi-antenna array. ML-DMU is a three-layer structure which is composed of two types of decoupling unit named top and bottom unit, middle unit, respectively. On this basis, the |S21| of proposed array is reduced to less than -23 dB from 2.36 GHz to 3.02 GHz while the antenna volume is not changed. The maximum gain of antenna element in the proposed antenna is 6.56 dBi at 3GHz, which is greater than the antenna without ML-DMU, but smaller than a single antenna element. Compared with other composite decoupling structures, the decoupling structure proposed in this paper has a more stable radiation performance and is simple and easy to install, which makes it have a good prospect in the field of 5G communication and the field of near-earth ground penetrating radar.

Yagi-antenna Array Loaded with Multi-layer Composite Decoupling Structure

2025-03-01

PIER C

Vol. 153, 81-86, 2025

doi:10.2528/PIERC25010201

download: 36

Deadbeat Control of Permanent Magnet Synchronous Motorized Spindle Based on Improved Parameter Identification Algorithm

Dazuo Zhou and Xin Wang

A deadbeat control method based on an improved parameter identification algorithm is proposed to improve the control accuracy and rapidity of permanent magnet synchronous motorized spindle (PMSMS). Firstly, based on the mathematical model of PMSMS and Euler discretization formula, the current prediction equation is established. Secondly, the deadbeat control logic is described; the deadbeat control model is established; and the influence of parameters on the system stability is analyzed. Thirdly, in order to improve the parameter robustness of deadbeat control, an improved adaptive parameter identification algorithm is proposed, which combines the least mean square algorithm and the recursive least square algorithm. Based on the voltage equation, the inductance and flux linkage parameters are identified, and then a more accurate parameter identification effect is achieved. Finally, the proposed algorithm is verified by experiments on the experimental platform. Experimental results show that the proposed algorithm has better control accuracy, faster response speed and stronger stability than vector control method and traditional deadbeat control method.

Deadbeat Control of Permanent Magnet Synchronous Motorized Spindle Based on Improved Parameter Identification Algorithm

2025-02-28

PIER C

Vol. 153, 71-80, 2025

doi:10.2528/PIERC24113002

download: 59

Magnetic Resonance Eddy Current Testing Based on Deep Learning Axis Identification and Reconstruction of Reinforced Concrete Penetration Image

Zhengxuan Zhang, Jinming Zhang and Leng Liao

Accurately identifying and calibrating reinforcement bars in concrete is a significant challenge due to their invisibility. This paper proposes a deep learning-based method using magnetic resonance eddy penetrating imaging (MREPI) to acquire data on steel bars embedded in concrete. The data is processed into images and input into the Skel-Unet neural network to extract angle and position information of the central axis of the steel bars. Based on this information, the steel bar diameters are determined. A novel image reconstruction method is also introduced to integrate rebar dimension variations for precise calibration. Experimental results show that the Skel-Unet model achieves high accuracy, with training and testing loss values below 0.01, and F1 score reaches 0.7436. The reconstructed images clearly delineate the position, dimensions, and orientation of the rebars, enhancing calibration and nondestructive testing in structural health monitoring.

Magnetic Resonance Eddy Current Testing Based on Deep Learning Axis Identification and Reconstruction of Reinforced Concrete Penetration Image

2025-02-27

PIER C

Vol. 153, 61-70, 2025

doi:10.2528/PIERC25011003

download: 28

Terahertz Metamaterial Devices with Switchable Absorption and Polarization Conversion Based on Vanadium Dioxide

Fang Wang, Junjie Cui, Hua Liu, Tao Ma, Xu Wang and Yufang Liu

This paper presents a switchable terahertz metamaterial device based on vanadium dioxide (VO₂). By leveraging its phase transition properties, the device achieves broadband absorption and polarization conversion functionality through the insulator-to-metal transition (IMT) induced by temperature modulation. When VO₂ is metallic, the device functions as a broadband absorber. achieving an absorption rate exceeding 90% within the frequency range of 2.2 to 4.4 THz. Conversely, when VO₂ is in its insulating state, the device enables polarization conversion of incident terahertz waves. Simulation results reveal that in this state, the cross-polarized reflection coefficient (Ryx) exceeds 0.8, while the co-polarized reflection coefficient (Rxx) is significantly suppressed, indicating efficient conversion from co-polarization to cross-polarization within the 1.4 to 2.1 THz range. Notably, the polarization conversion rate approaches unity in this frequency band. Additionally, the study investigates the influence of the structure's geometric parameters, incident angle, and polarization angle on its performance. The results highlight the device's robust tolerance to variations in these parameters, as well as its low manufacturing precision requirements. The proposed multifunctional switchable terahertz metamaterial device holds significant potential for applications in terahertz research, polarization filtering, and terahertz invisibility technologies.

Terahertz Metamaterial Devices with Switchable Absorption and Polarization Conversion Based on Vanadium Dioxide

2025-02-27

PIER C

Vol. 153, 51-59, 2025

doi:10.2528/PIERC24112901

download: 44

Optimization Design for Bionic-Bamboo FPs of Coaxial Magnetic Gear Under Multi-Field Coupling

Yufeng Zhou, Heng Yang, Shuai Luo and Xiuhong Hao

Coaxial magnetic gear (CMG) with magnetic field modulation mechanism features high torque density, non-contact transmis-sion, and overload automatic protection, making it an optimal substitute for mechanical gears. Considering the unbalanced mag-netic pull caused by the modulation effect of magnetic field and the component eccentricities, the deformations of the key fer-romagnetic pole-pieces (FPs) are analyzed with and without magnetic-force-structure multi-field coupling. Then, the segmenta-tion and reinforcement ideas based on bionic-bamboo are proposed in order to reduce the deformation of FPs. The functional relationships among FPs structural parameters, the output torque of CMG and the deformation of FPs are established with the orthogonal test method and response surface method. Based on NSGA-Ⅲ, the optimal parameters of FPs are obtained, and the corresponding deformation is greatly reduced. Finally, it is proved that the bionic-bamboo FPs can effectively reduce its defor-mation by the experiment and finite element simulation.

Optimization Design for Bionic-bamboo FPs of Coaxial Magnetic Gear under Multi-field Coupling

2025-02-27

PIER C

Vol. 153, 45-50, 2025

doi:10.2528/PIERC25010602

download: 52

Design and Performance Evaluation of Ku-Band Positive Feedback Push-Push Oscillator Using Square Split-Ring Bandpass Filter

Elton Nascimento Lima, Takayuki Tanaka and Ichihiko Toyoda

This paper presents a low phase noise positive feedback type Push-Push oscillator employing a balanced bandpass filter (BPF). The BPF consists of an array of split-ring resonators and functions as a frequency selective element in the common feedback loop of the oscillator. Two positive feedback oscillators are coupled to create the 180-degree differential signals required for the implementation of a Push-Push oscillator. The proposed oscillator is analyzed and fabricated. The measured results show that the oscillator works at 15.15 GHz of the second harmonic frequency with an output power of -5.6 dBm. Furthermore, the suppression of fundamental frequency signal is 25.2 dB. Excellent phase noise performance of -100.37 dBc/Hz at 100-kHz offset frequency and -127.13 dBc/Hz at 1-MHz offset frequency is obtained.

Design and Performance Evaluation of Ku-band Positive Feedback Push-push Oscillator Using Square Split-ring Bandpass Filter

2025-02-24

PIER C

Vol. 153, 33-43, 2025

doi:10.2528/PIERC24110605

download: 68

Design and Fabrication of SRR Loaded Cantor Fractal Slotted DGS Antenna Using Quarter Wave Transformer Fed for Microwave C-Band Communication

Anuj Kumar Sharma, Vipul Sharma and Sanjay Singh

The design, fabrication, and measurement of a 70 mm × 60 mm × 1.6 mm high-bandwidth Cantor fractal slotted defected ground surface (DGS) antenna for the microwave C-band (4-8 GHz) are presented in this study. This multiband antenna has the best performance ever because it combines a Cantor-inverted Cantor fractal slot with a microstrip quarter-wave transformer feeding network. With simulated operating bands spanning 3.37-3.48 GHz, 4.22-5.67 GHz, and 6.74-8.25 GHz, this antenna demonstrates exceptional simulated impedance bandwidths of 110 MHz, 1.43 GHz, and 1.51 GHz with simulated reflection coefficients of -27.22 dB, -28.23 dB, and -14.71 dB at resonance frequencies of 3.44 GHz, 5.03 GHz, and 7.17 GHz, respectively. Furthermore, the antenna exhibits simulated high gains of 5.6 dB, at 5.03 GHz resonating frequency. The introduction of a split ring resonator (SRR) at the ground surface unlocks the complete simulated bandwidth of 4.13-8.14 GHz and boosts the simulated gain to 6.1 dB. The design of this SRR at 5.03 GHz shifts one band from 3.44 GHz to 2.97 GHz with simulated bandwidth of 60 MHz. The VSWR value of this design is very close to 1. Consequently, its good impedance matching enhances the antenna's wideband performance. This is beneficial because patch antennas usually have a limited bandwidth. In addition, the antenna simulation displays an exactly symmetrical radiation pattern with current densities of 268 A/m and 155 A/m at 5.03 GHz with and without SRR, respectively.

Design and Fabrication of SRR Loaded Cantor Fractal Slotted DGS Antenna using Quarter Wave Transformer Fed for Microwave C-band Communication

2025-02-23

PIER C

Vol. 153, 25-32, 2025

doi:10.2528/PIERC25010401

download: 60

Wideband Tunable Filter of Dual-Path Microstrip Coupled-Lines with Varactor Tuned Circuit

Siti Aminah Nordin, Muhammad Asraf Hairuddin, Zakiah Mohd Yusoff, Gaetan Prigent and Nur Dalila Khirul Ashar

This study presents a compact and tunable microstrip of a dual-path wideband filter that employs coupled-lines and varactors to address the needs of 4G/sub-6 GHz 5G communication systems. This work integrates tunable methods inspired by wideband parallel coupled line-based topologies to realize a reconfigurable solution achieving a 34% frequency tuning range (1.13-1.51 GHz) while maintaining a low insertion loss of approximately below 1 dB. Specifically, the proposed microstrip-based filter, which is designed, uses parallel coupled-line resonators with a quarter-wavelength length, enabling a broad tuning range between 1.27 and 1.54 GHz. Adjusting the coupling strengths of both adjacent and non-adjacent resonators, the filter can be shifted within this frequency band without compromising performance. Therefore, to achieve the desired level of control, two identical varactor diodes and biasing circuitry are meticulously selected for their stable and repeatable capacitance-voltage characteristics to adjust the filter's resonant frequency. The optimal positions for these tuning circuits are determined based on the resulting capacitance, which is crucial for achieving a wide tuning range. Simulation and measurement confirm that this reconfigurable microstrip filter, implemented on a 60.7 x 35.4 mm² footprint, benefits not only from a reduced footprint but also from the ability to target multiple frequency bands with minimal hardware modifications, delivering the intended performance for modern wireless front ends.

Wideband Tunable Filter of Dual-path Microstrip Coupled-Lines with Varactor Tuned Circuit

2025-02-22

PIER C

Vol. 153, 13-23, 2025

doi:10.2528/PIERC24122504

download: 56

High Accurate PMSM Computation Model Based on Strongly Coupled Magnetic Field and Multi-Turns Electric Winding Circuits Using the Time-Stepping Finite Element

Tarik Merzouki and M'hemed Rachek

The work presented in this paper has great significance in improving electromagnetic models based on the strong coupling between the magnetic and electric fields transient equations while considering a realistic random multi-turn stranded winding where eddy currents, proximity and skin effects occur. The space-time partial differential equations of electromagnetic field expressed in terms of magnetic vector potential under nonlinear (B-H) magnetic materials curves handled by the iterative Newton-Raphson (NR) algorithm are simultaneously coupled with the voltage fed multi-turns electric circuits equations based on Kirchhoff's voltage law for each turn coil current loop. The magnetic field-multi-turn electric circuit coupled model solved using the time-stepping finite element method (FEM) formulation is dedicated to highly accurate computation of electromagnetic-mechanical devices. The developed FEM tools implemented under Matlab software are used to the modeling of the permanent magnet synchronous motor (PMSM) behavior through the physical quantities such as magnetic flux density, electric current, electromagnetic torque, and angular velocity.

High Accurate PMSM Computation Model Based on Strongly Coupled Magnetic Field and Multi-turns Electric Winding Circuits Using the Time-stepping Finite Element

2025-02-21

PIER C

Vol. 153, 1-12, 2025

doi:10.2528/PIERC24123001

download: 64

A Miniaturized UWB MIMO Antenna Design for 5G Multi-Band Applications

Shanhua Yao, Xiaorong Qiu and Tianchu Yang

In this paper, an ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna covering the n77, n78, n79, and 6 GHz bands is proposed for 5G applications, which achieves the full coverage of the 5G NR (New Radio) band with a compact geometry. The antenna is fabricated from low-cost printed circuit boards, with the dimensions of 36 mm x 53 mm x 1.6 mm. The MIMO antenna has been designed with two positive octagonal antenna monopole elements, which feature triangular fractal slots and a defected ground plane. Each of these elements is excited by a microstrip feed, and the antenna operates within a bandwidth of 2.92-16.97 GHz, which encompasses the entire UWB frequency range. The utilization of a floor with T-shaped slots and T-shaped stubs serves to minimize the generation of coupling currents between the antenna elements, thereby achieving an isolation of in excess of 19 dB across the entire operating band and a figure in excess of 20 dB in multiple 5G bands. In addition, simulations and measurements show that the antenna has an envelope correlation coefficient (ECC) less than 0.005, a diversity gain (DG) more than 9.98, a total active reflection coefficient (TARC) less than -30 dB, and a channel capacity loss (CCL) less than 0.3 bit/s/Hz in the operating frequency band, with good gain and stable radiation characteristics. The designed antenna has the potential for significant applications in 5G wireless communications.