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Vol. 140, 193-201, 2024
download: 73
Analysis and Design of an S-CL Compensated WPT System with Dual-Type Output Function
Qingsong Sang , Yilin Wang , Lin Yang and Xuebin Zhou
Simultaneous realization of load-independent dual-type output, namely constant current output (CCO) and constant voltage output (CVO), is necessary in some wireless power transmission (WPT) application fields. Therefore, an S-CL compensated WPT system with dual-type output function is proposed in this paper. This proposed system consists of a two-coil loosely coupled transformer(LCT)which can avoid cross-coupling phenomena, a transmitter-side compensation capacitor, a receiver-side compensation capacitor and a receiver-side compensation inductor. Meanwhile, the proposed system can achieve near zero-phase-angle (ZPA) and zero-voltage-switching (ZVS) operations, avoiding power losses caused by reactive circulation. In addition, the theoretical analysis of the system's constant voltage and constant current outputs are further elaborated in this paper, and a test prototype is fabricated to verify the rationality and implementability of the proposed WPT system.
Analysis and Design of an S-CL Compensated WPT System with Dual-type Output Function
Vol. 140, 185-192, 2024
download: 91
GA Based Optimization Technique for Magnetic Field Attenuation Around High Voltage Overhead Transmission Lines Using Mechanical Rearrangement of Power Conductors
Eslam Mohamed Ahmed and Khaled Hosny Ibrahim
The magnetic field produced by overhead high voltage transmission lines has received extensive attention owing to its possible biological effects on humanity. The scientific community as well as general public are interested in the possible threats that living things may pose from the magnetic field. This research proposes a magnetic field mitigation approach near an overhead transmission line to avoid negative impact on the population around these lines. Apart from altering human brain activity and heart rate, magnetic fields can also lead to diseases like cancer. As a result, many techniques are employed to lessen that magnetic field. To reduce this magnetic field, scientists are looking for transmission line schemes. The suggested study investigates the influence of mechanical rearranging power conductors on magnetic field mitigation using genetic algorithm (GA) which is one of the evolutionary optimization techniques. The proposed GA has the objective to minimize the magnetic field as a fitness function and the location of conductors as genes considering their symmetry. The proposed method is tested using two published study cases of actual overhead transmission lines resulting in 48.4% and 57% reduction in magnetic field for case1 and case2, respectively. The contribution of the proposed method is to provide higher mitigation level of the mechanical rearrangement method depending on different sub-conductors spacing for one phase. The proposed mechanical rearrangement increases the geometric mean radius of the inner phase by optimizing its sub-conductors spacing within allowable critical ranges, thus the practical implementation of the proposed method requires a special design of the inner insulators string to support its sub-conductors.
GA Based Optimization Technique for Magnetic Field Attenuation around High Voltage Overhead Transmission Lines Using Mechanical Rearrangement of Power Conductors
Vol. 140, 177-184, 2024
download: 90
4-Ports Small Size Metamaterial Antenna with Electromagnetic Walls for MIMO Systems
Cristopher Pineda-Salgado , José Alfredo Tirado-Méndez , Hildeberto Jardon-Aguilar , Ruben Flores-Leal , Arturo Rangel-Merino and Jaime Pedro Abarca-Reyna
In this paper, a very small 4-port MIMO antenna is designed, based on a metamaterial structure composed of embedded octagonal Split-Ring Resonators (SSRs). The antenna array shows an axial symmetry configuration with dimensions of 32 × 32 mm2, corresponding to 0.157λ2, approximately, related to a center frequency of 3.5 GHz, with a high electromagnetic isolation despite the radiators' closeness, reaching values bigger than 26 dB for adjacent antennas, and more than 28 dB for opposite antennas. The antenna is built on a substrate with dielectric permittivity of 2.2 and 1.27 mm thick. The Total Active Reflection Coefficient (TARC) presents a steady behavior for different random phases at the incoming signals, keeping a system bandwidth of 0.9 GHz for a -10 dB value. On the other hand, the Envelope Correlations Coefficient (ECC) reports values lower than 0.001 in all the antenna relationships, achieving a very uncorrelated performance of the electric fields in each element. The radiation pattern is quasi-omnidirectional, obtaining a low gain around -2 dBi, a trade-off that is considering the size reduction of the MIMO antenna.
4-ports Small Size Metamaterial Antenna with Electromagnetic Walls for MIMO Systems
Vol. 140, 163-175, 2024
download: 145
Enhanced Far-Field Localization Scheme Using Multi-RIS and Efficient Beam Sweeping
Abdulrhman Kh. Alhafid , Sedki Younis and Yessar Ezzaldeen Mohammed Ali
Future 6G networks are anticipated to use reconfigurable intelligent surfaces (RISs) because of their capability to expand coverage, provide a customizable wireless environment, increase localization accuracy, etc. In this paper, RIS-aided localization is considered with orthogonal frequency division multiplexing (OFDM) and single-input single-output (SISO) downlink system in millimeter-wave (mmWave). An efficient beam sweeping (EBS) scheme is proposed accomplished by an RIS to scan the area of interest and estimate the direction of the user equipment (UE), i.e., the signal's angle of departure (AoD). The AoD with the measured signal time of arrival (ToA), from the RIS to the UE, is used to estimate the UE position. The ToA measurements can be obtained by exploiting the OFDM signal, while the beam sweeping can be obtained by carefully designing the RIS phase profile. The first step of the proposed EBS scheme is to scan the whole area of interest with equally spaced beam angles for coarse estimation of AoD. Then, based on this estimation, the RIS is reconfigured to sweep a slight angle's range by narrow beams to refine the AoD estimation. Besides, a multi-RIS scenario is proposed, and leveraging the EBS and the consensus fusion method is used to obtain accurate position estimation. Simulation results demonstrate that the proposed EBS in single and multi-RIS scenarios enhances positioning accuracy compared to linear beam sweeping (LBS) methods. Also, the impact of increasing the number of RIS elements and number of sweeping beams, as well as the number of RISs, is investigated thoroughly via numerical simulations. Furthermore, the achievable localization accuracy is assessed using the positioning error bound (PEB).
Enhanced Far-field Localization Scheme Using Multi-RIS and Efficient Beam Sweeping
Vol. 140, 151-161, 2024
download: 102
An Ultra-Wideband Antenna Based on Left-Handed Materials for IoT Applications
Jincheng Xue , Ao Ni , Lanzheng Liu , Zhuopeng Wang and Xia Wang
In this paper, a new UWB antenna for the Internet of Things (IoT) based on a left-handed structure is designed. The antenna utilizes a microstrip feeder and consists of a new complementary split ring resonator (CSRR) equipped with a three-stage double rectangular electromagnetic resonator (RER) to form the main radiator with left-handed characteristics. It also includes a double L-shaped parasitic patch and a slotted ground. The dimensions of the antenna are 0.42×0.42×0.013λ03. It covers the frequency band of 1.70-3.34 GHz (65.1%), which includes the communication frequency bands used by IoT antennas. The antenna exhibits good directional patterns within this frequency band. The measured peak gain is 5.49 dBi, making it suitable for applications in Wi-Fi, Bluetooth, Zigbee technology, and other fields.
An Ultra-wideband Antenna Based on Left-handed Materials for IoT Applications
Vol. 140, 145-150, 2024
download: 110
Tumour Detection in Fabricated Gelatin Brain Phantom Model Using Ultra Wide Band Planner Antenna
Hemant Kumar Gupta and Vandana Vikas Thakery
This paper describes the design of an antenna and the development of a brain phantom model to validate the simulation results. The fabricated design of the phantom is interfaced with fabricated antenna, and the tumour in the fabricated phantom brain model is detected by return loss variation of the transmitted and reflected signals. Antennas are designed at the 2.45 GHz ISM (Industrial Science Medical) band and 5.8 GHz, and the lengths and widths for rectangular microstrip patch antenna (RMPA) have been calculated from the standard design equations. Different types of defects are applied in the front plane and ground plane of the antenna. Defect Ground Structures (DGSs) are applied to make the antenna ultra-wideband (UWB), because UWB is the basic requirement of antenna used in tumour detection applications. The design of gelatine brain phantom models with tumour and tumour-free is described. Finally, the brain phantom design is Interfaced to each deigned antenna. The tumour in brain is detected by variations in the incident and reflected wave reflection loss parameter.
Tumour Detection in Fabricated Gelatin Brain Phantom Model Using Ultra Wide Band Planner Antenna
Vol. 140, 135-144, 2024
download: 255
Design and Analysis of Low Profile Stepped Feedline with Dual Circular Patch MIMO Antenna and Stub Loaded Partial Ground Plane for Wireless Applications
Praveen Kumar , Ajit Kumar Singh , Ranjeet Kumar , Santosh Kumar Mahto , Pravesh Pal , Rashmi Sinha , Arvind Choubey and Ahmed Jamal Abdullah Al-Gburi
A wideband, dual-element MIMO antenna operating in the 2.83-7.21 GHz frequency bands is presented in this study. The proposed design consists of a stub-loaded partial ground plane and a stepped feedline with a dual circular-shaped radiator on top. The designed MIMO antenna operates from 2.83-7.21 GHz, covering the C band (4-8 GHz) and 5G (sub-6 GHz) applications. The peak gain observed is 4.8 dBi at 6.2 GHz, with a maximum efficiency of 92% at 3.2 GHz. The minimum port isolation and ECC over the bands 2.83-7.21 are observed as 22 dB and 0.003, respectively. To achieve the best outcome, a parametric analysis of the proposed antenna is also simulated. Various diversity characteristic metrics, including diversity gain (DG), mean effective gain (MEG), total active reflection coefficient (TARC), channel capacity loss (CCL), and ergodic channel capacity (CC), are thoroughly analyzed to determine how well the MIMO antenna performs in terms of diversity. In all operating bands, the measured values provide good agreement with simulation results, indicating a strong candidacy for operation in the investigated bands.
Design and Analysis of Low Profile Stepped Feedline with Dual Circular Patch MIMO Antenna and Stub Loaded Partial Ground Plane for Wireless Applications
Vol. 140, 127-134, 2024
download: 154
A Flexible UWB Slot Antenna with Quad Band-Notched Characteristics for Wearable Application
Tian-Shi Wang , Chengzhu Du , Hai-Feng Shu and Zhi-Hua Yue
The design and analysis of a compact coplanar waveguide (CPW) fed wearable slot antenna with four notched bands for Ultra-Wideband (UWB) applications are presented in this paper. The antenna is printed on a 0.1-millimeter-thick Liquid Crystal Polymer (LCP) substrate, providing flexibility for wearable applications. Split Concentric Rings (SCRs) engraved on the radiating patch and branches in L form loaded on the ground plane provide the antenna's notched features. The impedance bandwidth of the measured antenna ranges from 2.46 GHz to 12.52 GHz, with a fractional bandwidth (FBW) of 134.1%,and it exhibits notched bands covering specific frequency ranges, ranging from 2.84 GHz to 3.93 GHz for WiMAX applications, 4.84 GHz to 5.41 GHz for WLAN downlink, 5.66 GHz to 6.26 GHz for WLAN uplink, and 6.94 GHz to 7.79 GHz for X-band satellite communication. Furthermore, the gain of the proposed antenna varies between 1.5 and 6 dBi, excluding the notched band. The antenna is tested, and the flexibility performance is good. In a word, the fabricated antenna shows promising prospects for wearable applications.
A Flexible UWB Slot Antenna with Quad Band-notched Characteristics for Wearable Application
Vol. 140, 117-126, 2024
download: 99
PMSM Parameter Identification Based on Chaotic Adaptive Search Grey Wolf Optimization Algorithm
Yang Zhang , Ziying Liu , Mingfeng Zhou , Sicheng Li , Jiaxuan Li and Zhun Cheng
Aiming at the problems of poor population diversity, slow speed of late identification and low identification accuracy of traditional grey wolf algorithm (GWO), a chaotic adaptive search grey wolf optimization algorithm (CASGWO) for parameter identification of permanent magnet synchronous motor is proposed in this paper. Firstly multiple low-dimensional chaotic mappings are combined; a composite chaotic system Tent-Logistic-Cosine is obtained; uniform populations are generated. So the population diversity and global search capability are improved. Then a segmented nonlinear search method is proposed, where the nonlinear decay factor quickly converges to the vicinity of the optimal solution in the first segment and slows down the convergence rate for local search in the second segment. Thus, the convergence rate is accelerated while the local search capability is enhanced. Finally, the adaptive inertia weights are adjusted according to the fitness values of different wolf pack iterations, and ω wolves approach the leader wolf pack with smaller fitness values at a faster speed. Therefore, the speed of search is again improved, and the local search ability of the algorithm is again enhanced. Experiments show that when identifying multiple parameters of resistance, inductance, and permanent magnet flux of a permanent magnet synchronous motor, the CASGWO method has good global and local search capability, with faster identification speed and higher identification accuracy than the traditional grey wolf algorithm.
PMSM Parameter Identification Based on Chaotic Adaptive Search Grey Wolf Optimization Algorithm
Vol. 140, 105-115, 2024
download: 114
Electromagnetic Characteristic Analysis and Optimization of a Novel Reverse Salient PMSM for Wide Speed Range
Ruipan Lu , Zhangqi Liu , Xiping Liu , Jianwei Liang , Weiliang Wu and Wenrui Wang
To address the issues associated with the conventional permanent magnet synchronous machine, particularly difficulties in adjusting the air-gap flux barrier and the limited range of constant power speed regulation, this paper introduces a novel approach. It combines the intensifying-flux effect with the permanent magnet synchronous machine to propose a new design known as the reverse salient permanent magnet synchronous machine (RS-PMSM) with a multilayered flux barrier. This innovation serves to enhance the working performance of the permanent magnets. The paper's structure includes an initial introduction to the RS-PMSM, outlining its structure and operational principles. Following this, an optimization approach employing NSGA-II is used to define the RS-PMSM's optimization model. The objectives of this optimization encompass torque, torque ripple, and the reverse salient pole ratio. The study then proceeds to conduct a comprehensive set of performance analyses and comparisons, involving the initial machine, the optimized machine, and a conventional machine. The performance metrics considered include no-load air-gap flux density, reverse electromotive force, torque characteristics, speed range, and efficiency. Finally, the study verifies the design rationality of the RS-PMSM, highlighting its potential to address the challenges posed by traditional permanent magnet synchronous motors.
Electromagnetic Characteristic Analysis and Optimization of a Novel Reverse Salient PMSM for Wide Speed Range
Vol. 140, 93-104, 2024
download: 113
UWB Resonator-Based Supervised Learning for Breast Tumor Diagnosis
Sonal Amit Patil and Ashwini Naik
This paper proposes an application of ultra-wideband antenna in conjunction with supervised machine learning to detect the existence of breast tumor. The microstrip line fed octagonal shaped UWB antenna is designed by using Ansys high-frequency structure simulator 2022 R2. It is fabricated on double sided copper FR4 epoxy glass substrate of size 40 mm × 40 mm and tested by using vector network analyzer N9916A. The antenna structure is optimized over the frequency spectrum of 3.1 GHz to 10.6 GHz to obtain minimum value of return loss. The optimized structure provides bandwidth spectrum of 8.38 GHz covering the frequency range of 2.76 to 11.15 GHz with maximum gain of 5.3 dB at 8 GHz. The homogenous artificial breast phantoms with and without tumor are fabricated using different chemical compositions. The dielectric traits of skin, fatty, glandular and tumor layers are analyzed. Microwave sensing for detecting the presence of breast cancer uses the disparity between tumor and breast tissues, requiring consideration of dispersiveness to accurately assess the dielectric characteristics of the breast model due to its lossy dispersive nature. The three sets of reflection characteristics of the entire system comprised of antenna with phantoms are recorded by using VNA with a gap of week to constitute the dataset. The ultrasonic gel serves as a medium for matching between the breast model and antenna. Further, the supervised machine learning approach is used to improve the detection accuracy. Supervised learning, a key category of machine learning, uses labeled data to predict unseen data. The Logistic Regression, Support Vector Machine, K-Nearest Neighbors, Random Forest and Multilayer Perceptron algorithms are applied on the measured data to classify the healthy and tumorous tissues. The random forest proven to be best fit on the data with auc score of 98.05%.
UWB Resonator-based Supervised Learning for Breast Tumor Diagnosis
Vol. 140, 85-91, 2024
download: 130
Modeling and Simulation of Photonic Crystal Sensor for Drinking Water Quality Monitoring
Farida Kebaili , Ahlam Harhouz and Abdesselam Hocini
Photonics crystal sensors, sensitive to light, play a crucial role in discerning minute alterations in a material's refractive index, finding widespread application, such as in monitoring drinking water quality. Our objective is to fashion a sensor based on a 2D photonics crystal structure and scrutinize optical transformations induced by variations in the bacteria's refractive index as light traverses the sensor structure. Leveraging Rsoft's simulation capabilities, we assessed transmission spectra, observing shifts in the bacteria's refractive index and their consequential impact on the light signal's frequency and wavelength within the sensor structure. The simulations unequivocally demonstrate that fluctuations in the bacteria's refractive index significantly affect the light signal's frequency and wavelength. Consequently, the study underscores the efficacy of the Rsoft-designed optical sensor in discerning bacterial presence in contaminated water, achieving an average sensitivity of 834 nm/RIU. In conclusion, the study establishes the success of the optical sensor crafted with Rsoft software in detecting bacteria in polluted water. By monitoring optical alterations during light traversal, variations in the bacteria's refractive index are translated into discernible shifts in the light signal's frequency and wavelength, facilitating effective bacteria detection.
Modeling and Simulation of Photonic Crystal Sensor for Drinking Water Quality Monitoring
Vol. 140, 75-84, 2024
download: 123
Broadband and Compact Design Variations of Z-Shaped Printed Slot Microstrip Antenna
Mandar Padmakar Joshi , Jayant Gajanan Joshi and Santosh P. Agnihotri
In this research work, a Z-shaped printed slot microstrip antenna with variations in feed location has been presented to realize broadband and compact antenna. The Z-shaped slot has been realized by placing two right angle triangle shaped patches in opposite directions inside rectangular shaped slot. Further by aligning the microstrip line as feed along the length and width of Z-shaped slot, the broadband and compact antenna respectively has been realized. The antenna is fabricated using an FR4 substrate having electrical dimension of 0.48λ0 × 0.4λ0. The antenna offers 407 MHz (27%) measured impedance bandwidth for broadband and 22% of reduction in size for compact configurations. The parametric analysis, equivalent circuit analysis and temperature as an environmental testing parameter of proposed designs are presented and validated in this paper.
Broadband and Compact Design Variations of Z-shaped Printed Slot Microstrip Antenna
Vol. 140, 65-73, 2024
download: 139
Antenna Sensor Based on an Inter-Digital Capacitor Shape EBG Structure for Liquid Dielectric Measurement
Bo Yin and Juntao Yin
In this paper, an antenna sensor based on an electromagnetic bandgap (EBG) structure is proposed to measure the complex permittivity of liquid under test (LUT). The sensor consists of two parts: a detection antenna and an EBG structure. The detection antenna uses a semicircular arc defective ground structure to improve the quality factor (Q-factor). Simultaneously, the EBG structure can be equivalent to a narrow-band bandpass filter, so that the electromagnetic wave can only propagate in a very narrow frequency band. It can further improve the Q-factor of the antenna and realize the precise positioning of the resonance frequency point. The complex permittivity of the LUT can be extracted by measuring the resonant frequency shift and the amount of variation in the Q-factor of the antenna. The test results show that the sensor can detect dielectric values covering the range of 1-25, and the average sensitivity is 2.342%. It combines the advantages of high sensitivity and wide detection range.
Antenna Sensor Based on an Inter-Digital Capacitor Shape EBG Structure for Liquid Dielectric Measurement
Vol. 140, 53-64, 2024
download: 81
An Enhanced Robustness Dual-Vector Model Predictive Torque Control for Permanent Magnet Synchronous Motors
Hao Xie , Cheng Zhang , Yang Zhang and Sicheng Li
The traditional dual-vector model predictive torque control (MPTC) of permanent magnet synchronous motor suffers from the problems of large control computation, large torque ripple, and prediction deviation due to parameter mismatch. To address these issues, an enhanced robustness dual-vector MPTC (ERD-MPTC) control strategy is proposed in this paper. First, in order to reduce the control computation, a fast voltage vector selection table based on a 12-sector voltage vector map is proposed, which reduces the number of prediction iterations from 14 to only 3. Secondly, to reduce the ripple of torque and flux in one cycle, the cost function without weight factor is proposed. This cost function includes the fluctuations at the moment of the switching point. Then, for the bad effects of parameter mismatch, the inductance parameter is estimated by using the amount of error variation between the predicted value and the actual measured value at adjacent moments. So, an ERD-MPTC strategy to enhance the robustness of the prediction model in the presence of parameter mismatch is proposed by integrating the inductance updating mechanism and expanded state observer. Finally, through the experiment, it is shown that the proposed strategy can reduce the torque fluctuation, effectively reduce the adverse effects of parameter changes, and greatly improve the stability of the system.
An Enhanced Robustness Dual-vector Model Predictive Torque Control for Permanent Magnet Synchronous Motors
Vol. 140, 41-51, 2024
download: 191
Low-Cost High Gain Sea Pimp-Shaped Dual Band Monopole Antenna for Mobile 4G/5G/LTE41/WLAN Application
Suwat Sakulchat , Amnoiy Ruengwaree , Watcharaphon Naktong , Pramuk Unahalekhaka and Sommart Promput
This research aimed to design a sea pimp-shaped monopole antenna by using etching and cutting techniques, combined with the addition of reflector, to modify the antenna structure to support the bandwidth standard according to GSM-850 (0.82-0.90 GHz), GSM-900 (0.88-0.96 GHz), DCS (1.72-1.88 GHz), PCS (1.85-1.99 GHz), UMTS (1.92-2.17 GHz), 5G Band40 (2.30-2.40 GHz), LTE41 (2.496-2.690 GHz), and WLAN IEEE 802.11b/g/n (2.4-2.48 GHz). This antenna used a galvanized metal sheet with a conductivity of 3.56 x 107 s/m to fabricate the structure of the radiator, ground plane, and reflector. The reflector modifies radiation patterns and increases the gain of the antenna. The antenna structure used the CST program for simulation to determine the optimal parameters and property values. As a result of replication, the antenna had a dual-band with a reflection coefficient S11 at 915 MHz (736-1040 MHz) of -26.70 dB and a frequency at 2.28 GHz (1.68-2.94 GHz) of -20.15 dB. The antenna gains are 6.70 and 8.47 dBi, an increase of 83.56% and 44.04% over the antenna without a reflector, respectively. The antenna had a unidirectional pattern in all the frequency ranges which can be utilized for the purpose of RF energy-harvesting (RF-EH) systems to provide power to low-power electronic systems.
Low-cost High Gain Sea Pimp-shaped Dual Band Monopole Antenna for Mobile 4G/5G/LTE41/WLAN Application
Vol. 140, 31-40, 2024
download: 204
Q -Learning Empowered Cavity Filter Tuning with Epsilon Decay Strategy
Amina Aghanim , Hamid Chekenbah , Otman Oulhaj and Rafik Lasri
In the ever-evolving landscape of engineering and technology, the optimization of complex systems is a perennial challenge. Cavity filters, pivotal in Radio Frequency (RF) systems, demand precise tuning for optimal performance. This article introduces an innovative approach to automate cavity filter tuning using Q-learning, enhanced with epsilon decay. While reinforcement learning algorithms like Q-learning have shown effectiveness in complex decision-making, the exploration-exploitation trade-off remains a crucial challenge. The study conducts a thorough investigation into the application of epsilon decay in conjunction with Q-learning, employing the well-established epsilon-greedy strategy. This research focuses on systematically decaying the exploration rateε over time, aiming to strike a balance between exploring new actions and exploiting acquired knowledge. This strategic shift serves to not only refine the convergence of the Q-learning model but also remarkably elevate the overall tuning performances. Impressively, this optimization is achieved with a notable reduction in the number of tuning steps, demonstrating an efficiency boost of up to 45 steps.
Q-Learning Empowered Cavity Filter Tuning with Epsilon Decay Strategy
Vol. 140, 21-30, 2024
download: 110
NGD Bandpass Type Characterization of Circular Curved Coupled-Line
Xirui Wang , Fayu Wan , Vladimir Mordachev , Eugene Sinkevich , Samuel Ngoho , Nour Mohammad Murad and Blaise Ravelo
The present study examines the negative group delay (NGD) behavior of a circular curved (CC) coupled-line (CL) microstrip circuit with a bandpass (BP) characteristic. The novel CC CL-based circuit is derived from the curved li-topology which demonstrates BP-NGD functionality. The basic theoretical approach enabling the BP-NGD analysis is introduced. The BP-NGD function main properties related to NGD center frequency, NGD value, and NGD bandwidth are defined. Despite the progressive NGD research work, it was wondered how the RF printed circuit board trace geometrical parameters such as curvature radius and angle change the microwave communication parameters. To verify the BP-NGD concept feasibility, different microstrip prototypes are designed, simulated, fabricated, and tested as the proof of concept (POC). Thus, a developed empirical study of CC microstrip structures corroborating well-correlated simulations and experimental results is examined. Moreover, deep sensitivity analyses for geometrical design parameters were performed using commercial tool full-wave simulations. The obtained results provide insights into the effects of CC-structure inter-space and curvature angles on the inherent BP-NGD parameters. The proposed NGD circuit is potentially useful in the future in RF and microwave engineering for signal delay correction. Additionally, it helps in understanding the characteristics of microstrip PCB traces that are important for optimizing signal integrity (SI), power integrity (PI), and electromagnetic compatibility (EMC).
NGD Bandpass Type Characterization of Circular Curved Coupled-line
Vol. 140, 11-19, 2024
download: 132
A Compact Dual-Band Dual-Polarized Antenna Based on Modified Minkowski Fractal
Mahmood T. Yassen , Ali Jabbar Salim , Mohammed R. Hussan and Jawad K. Ali
The polarization of the received signals can be effectively matched regardless of the orientation of the receiving antenna using circularly polarized antennas. A compact printed monopole antenna with a circular ring patch is presented in this paper. The proposed antenna will be able to provide two polarization states: linear and circular. The employment of a modified Minkowski fractal with 1st iteration construction on an open circular ring supports a circularly polarized band having a center frequency of 1.812 GHz and fractional bandwidth (FBW) of 20.033%. The upper band is achieved with a linearly polarized wave having a center frequency of 3.386 GHz and a fractional bandwidth of 11.399%. The proposed antenna is fed by an ungrounded co-planar waveguide (UCPW), enhanced with an impedance transformer to match at 50 ohms with the characteristic impedance. The ground planes around the feed line are defected by ground structures to improve the antenna gain. The fabrication and measurement of the proposed antenna prototype are presented to validate the theoretical results. Measured results support the theoretical findings well.
A Compact Dual-band Dual-polarized Antenna Based on Modified Minkowski Fractal
Vol. 140, 1-9, 2024
download: 134
Flux Weakening Control and Experimental Verification of Hybrid Excitation Field Modulation Synchronous Machine for Direct Drive Propulsion
Jiming Luo , Yang Zhang , Enzhao Lu , Quanzhen Huang , Mingming Huang and Duane Decker
With combining the advantages of the hybrid excited machine and field modulation machine, hybrid excitation field modulation machine (HEFMM) exhibits obvious merits of controllable flux operation and independent flux distributon paths. A total copper loss minimization model is established to determine the optimal ratios of field current, d-axis and q-axis currents in low speed region. In high speed operating region, one flux weakening fuzzy control strategy combining with particle swarm optimization (PSO) algorithm for HEFMM was proposed, which improves the dynamic characteristic and decrease the harmful influence of parameters variation during the operation region of HEFMM. The correctness and effectiveness of the proposed flux weakening fuzzy control strategy were verified by the simulation data and experimental results, which demonstrated that the this current optimization method based on PSO algorithm can effectively reduce the total copper loss of the machine by 22%, the range of speed regulation with higher efficiency are ontained.
Flux Weakening Control and Experimental Verification of Hybrid Excitation Field Modulation Synchronous Machine for Direct Drive Propulsion