Vol. 76
Latest Volume
All Volumes
PIERB 109 [2024] PIERB 108 [2024] PIERB 107 [2024] PIERB 106 [2024] PIERB 105 [2024] PIERB 104 [2024] PIERB 103 [2023] PIERB 102 [2023] PIERB 101 [2023] PIERB 100 [2023] PIERB 99 [2023] PIERB 98 [2023] PIERB 97 [2022] PIERB 96 [2022] PIERB 95 [2022] PIERB 94 [2021] PIERB 93 [2021] PIERB 92 [2021] PIERB 91 [2021] PIERB 90 [2021] PIERB 89 [2020] PIERB 88 [2020] PIERB 87 [2020] PIERB 86 [2020] PIERB 85 [2019] PIERB 84 [2019] PIERB 83 [2019] PIERB 82 [2018] PIERB 81 [2018] PIERB 80 [2018] PIERB 79 [2017] PIERB 78 [2017] PIERB 77 [2017] PIERB 76 [2017] PIERB 75 [2017] PIERB 74 [2017] PIERB 73 [2017] PIERB 72 [2017] PIERB 71 [2016] PIERB 70 [2016] PIERB 69 [2016] PIERB 68 [2016] PIERB 67 [2016] PIERB 66 [2016] PIERB 65 [2016] PIERB 64 [2015] PIERB 63 [2015] PIERB 62 [2015] PIERB 61 [2014] PIERB 60 [2014] PIERB 59 [2014] PIERB 58 [2014] PIERB 57 [2014] PIERB 56 [2013] PIERB 55 [2013] PIERB 54 [2013] PIERB 53 [2013] PIERB 52 [2013] PIERB 51 [2013] PIERB 50 [2013] PIERB 49 [2013] PIERB 48 [2013] PIERB 47 [2013] PIERB 46 [2013] PIERB 45 [2012] PIERB 44 [2012] PIERB 43 [2012] PIERB 42 [2012] PIERB 41 [2012] PIERB 40 [2012] PIERB 39 [2012] PIERB 38 [2012] PIERB 37 [2012] PIERB 36 [2012] PIERB 35 [2011] PIERB 34 [2011] PIERB 33 [2011] PIERB 32 [2011] PIERB 31 [2011] PIERB 30 [2011] PIERB 29 [2011] PIERB 28 [2011] PIERB 27 [2011] PIERB 26 [2010] PIERB 25 [2010] PIERB 24 [2010] PIERB 23 [2010] PIERB 22 [2010] PIERB 21 [2010] PIERB 20 [2010] PIERB 19 [2010] PIERB 18 [2009] PIERB 17 [2009] PIERB 16 [2009] PIERB 15 [2009] PIERB 14 [2009] PIERB 13 [2009] PIERB 12 [2009] PIERB 11 [2009] PIERB 10 [2008] PIERB 9 [2008] PIERB 8 [2008] PIERB 7 [2008] PIERB 6 [2008] PIERB 5 [2008] PIERB 4 [2008] PIERB 3 [2008] PIERB 2 [2008] PIERB 1 [2008]
2017-06-27
PIER B
Vol. 76, 141-157, 2017
download: 629
Scattering and Radiation Characteristics of Antenna Systems Under Nose Dielectric Radomes
Oleg Sukharevsky , Vitaly Vasylets and Sergey V. Nechitaylo
The calculation method for electromagnetic field scattered by antenna placed inside nose dielectric radome is proposed. To obtain the radiation characteristics, we use the calculation method for field generated by radiation aperture given that an arbitrary system of scatterers (particularly, radome) exists in its vicinity. Also, the method for calculating radiation characteristics of antenna system with the same radomes is obtained. Considered numerical results tell us that influence of radome on radiation characteristics can be reduced to minimum for any radome type. Besides, the radome can reduce the radar visibility of antenna system outside of its operating frequency range.
SCATTERING AND RADIATION CHARACTERISTICS OF ANTENNA SYSTEMS UNDER NOSE DIELECTRIC RADOMES
2017-06-26
PIER B
Vol. 76, 125-140, 2017
download: 301
A Method of Tracking Optimum Efficiency for Four-Coil Wireless Power Transfer System
Zhongqi Li , Yixiong Lai , Jiliang Yi and Junjun Li
Magnetic resonant wireless power transfer (WPT) is an emerging technology that may create new applications for wireless power charging. However, low efficiency resulting from the change of the transfer distance is a main obstructing factor for promoting this technology. In this paper, a method of fast tracking optimum efficiency is proposed. The input impedance value is obtained by measuring the input current. Then the transfer distance is estimated by the input impedance value. The optimum load resistor is obtained under a given transfer distance. In addition, the extended L-matching network is proposed in order to automatically adjust the load resistor. The key parameters of the matching network are also given. The optimum efficiency can be fast tracked by the proposed method as the transfer distance varies. The WPT system and the extended L-matching network are designed. Simulated and experimental results validating the proposed method are given.
A METHOD OF TRACKING OPTIMUM EFFICIENCY FOR FOUR-COIL WIRELESS POWER TRANSFER SYSTEM
2017-06-23
PIER B
Vol. 76, 111-123, 2017
download: 390
Fast Design of Asymmetrical Permanent Magnet Synchronous Machines That Minimize Pulsating Torque
Alejandro J. Pina Ortega
Torque pulsations in Permanent Magnet Synchronous Machines are mainly created by interaction between the permanent magnets and stator teeth, harmonics in the stator current, steel saturation and partial magnet demagnetization. As a consequence of torque ripple, there are increased noise and vibrations. To overcome them, some methods for reducing pulsating torque include controlled-asymmetry. The strategy seeks for compensate or cancel out spatial harmonics of flux density in the air gap. This work proposes an analytical method based upon sub-domain model that allows techniques such as stator teeth pairing, slot opening shift, nonuniform teeth, tangential shift of magnets, different magnet widths, among others, to be utilized and quickly analyzed. Since asymmetries introduce several degrees of freedom, the design of Permanent Magnet Synchronous Machines can be accelerated by means of analytical-based tools. The proposed model is validated with Finite Element method.
FAST DESIGN OF ASYMMETRICAL PERMANENT MAGNET SYNCHRONOUS MACHINES THAT MINIMIZE PULSATING TORQUE
2017-06-20
PIER B
Vol. 76, 97-110, 2017
download: 306
Motion of Small Spherical Particles in an Arbitrary Oriented Cluster Due to the Microwave Propagation
Aslan Nouri Moqadam , Ali Pourziad and Saeid Nikmehr
The electromagnetic (EM) waves influence substances involved in the propagation medium which leads to deviation or modification. Atomic stresses and strains caused by EM radiation make electromagnetic waves able to stir small particles by exertion of Lorentz force on them which is employed to deviate particles in this paper. The particles are considered as millimeter and micrometer-sized spheres with random electrical properties. Generalized Multi-Particle Mie theory (GMMT) is used to calculate scattering parameters such as Radar Cross Section for aggregates of arbitrarily oriented particles. The direction of motion caused by exerted Lorentz force on particles is accurately obtained in terms of Discrete Dipole Approximation (DDA). A bulk model based on Effective Medium Theory is designed to analyze the scattering parameters of particles, much smaller than incident wavelength. Application of this model is validated by several simulations. The profile of arbitrary incident wave and its amplitude and polarization effects on deviation are investigated, respectively. Numerical results are derived for various arbitrary orientations and different electromagnetic conditions.
MOTION OF SMALL SPHERICAL PARTICLES IN AN ARBITRARY ORIENTED CLUSTER DUE TO THE MICROWAVE PROPAGATION
2017-06-20
PIER B
Vol. 76, 87-96, 2017
download: 355
Advanced Multi-Pass InSAR Imaging for Surface Deformation Studies
Sui Ping Lee , Yee Kit Chan and Tien Sze Lim
This paper describes a multi-pass InSAR imaging approach for surface deformation studies. Such a technique extends concept of SAR tomography (TomoSAR) based on multi-pass InSAR data, in order to produce deformation map in elevation domain and velocity domain, respectively. Compared to conventional InSAR method, multi-pass InSAR imaging technique acquires multi-baseline information and allows reconstruction of multiple scattering sources in Tomo-Doppler plane (Elevation-Velocity plane). This technique offers a solution to layover issue over conventional InSAR method, but it suffers from double-scattering problem. This paper simulates a phenomenon where double-scattering impairs the imaging process and an improved solution method to separate single and double scatters from inferring pixels. In real circumstance, there are still other interferometric issues such as phase ambiguities of noise and phase discontinuity. Thus, a phase-unwrapping method associated with an improved ordered-statistical lter is included for interferometry processing. An experiment based on real SAR data is set up to demonstrate this technique.
ADVANCED MULTI-PASS INSAR IMAGING FOR SURFACE DEFORMATION STUDIES
2017-06-19
PIER B
Vol. 76, 73-85, 2017
download: 791
SRR Superstrate for Gain and Bandwidth Enhancement of Microstrip Patch Antenna Array
Chirag Arora , Shyam Sundar Pattnaik and Rudra Narayan Baral
This article presents a microstrip fed patch antenna array, loaded with metamaterial superstrate. An unloaded antenna array resonates at IEEE 802.16a 5.8 GHz Wi-MAX band with gain of 4.3 dBi and bandwidth of 425 MHz whereas when the same array is loaded with a metamaterial superstrate, composed of the pair of Split Ring Resonators (SRR), there is simultaneous gain and bandwidth improvement to 8 dBi and 680 MHz, respectively, which corresponds to gain improvement by 86% and bandwidth enhancement of 60%. The fabrication of this proposed antenna array is done, and its simulated and measured results compared. Equivalent circuit model of this composite structure has been developed and analyzed. The electrical dimension of the patch is 0.23λx0.3λ.
SRR SUPERSTRATE FOR GAIN AND BANDWIDTH ENHANCEMENT OF MICROSTRIP PATCH ANTENNA ARRAY
2017-06-14
PIER B
Vol. 76, 59-71, 2017
download: 238
Data-Driven Strategies for Cross-Track Motion Compensation in Synthetic Aperture Radar Imaging
Po-Chih Chen and Jean-Fu Kiang
Nine different strategies are proposed to compensate the cross-track motion errors in synthetic aperture radar (SAR) imaging, based on estimating the phase coefficients of the phase history. A spline interpolation method and a subaperture reconstuction method are used to derive the phase history over the whole aperture, based on the phase coefficients previously estimated. Four different scenarios are designed to compare the performance of these nine strategies.
DATA-DRIVEN STRATEGIES FOR CROSS-TRACK MOTION COMPENSATION IN SYNTHETIC APERTURE RADAR IMAGING
2017-06-14
PIER B
Vol. 76, 37-57, 2017
download: 477
Study of the Conducted Electromagnetic Interference in the Converter Station of an UHVDC Transmission System
Jian Le , Cao Wang , Hanwu Luo , Tao Mao and Yinge Wang
The Conducted Electromagnetic Interference (CEI) characteristics in the primary circuit and at the ports of the secondary devices of the converter station of a UHVDC transmission system are researched comprehensively and systematically in this paper, by taking the Zhalute-Qingzhou ±800kV/10000MW UHVDC project in East Inner Mongolia of China as an example. The primary circuit equipment parameters of the target system are designed systematically at first, and the overall broadband equivalent model of the main circuit of the UHVDC system, which is composed of converter valve, converter transformer, filter banks and smoothing reactor, is developed. The CEI characteristics in the primary circuit under various conditions of the UHVDC system are analyzed based on the simulations carried out on the built BEC, and the influences of several primary circuit elements on the propagation of the CEI characteristics are researched. To improve the accuracy of the analysis of the CEI characteristics in the secondary device circuit, accurate BECs of the Capacitor Voltage Transformer (CVT), Current Transformer (CT) and secondary signal cable are established. The CEI characteristics at the ports of secondary devices under different operation modes are studied, and the influences of the cable length and burden rate on the CEI characteristics are analyzed. This paper provides a comprehensive and thorough understanding of the CEI characteristics of an UHVDC system.
STUDY OF THE CONDUCTED ELECTROMAGNETIC INTERFERENCE IN THE CONVERTER STATION OF AN UHVDC TRANSMISSION SYSTEM
2017-06-10
PIER B
Vol. 76, 23-36, 2017
download: 358
Analytical Method Using Virtual PM Blocks to Represent Magnet Segmentations in Surface-Mounted PM Synchronous Machines
Tow Leong Tiang , Dahaman Ishak , Chee Peng Lim and Mohd Rezal Mohamed
This paper describes an analytical subdomain model to predict the magnetic field distributions in the semi-closed surface-mounted permanent magnet synchronous machines (PMSMs) due to magnet segmentations with radial magnetization (RM). The magnet segments per pole can be virtually represented by finite number of permanent magnet (PM) blocks and Fourier decompositions. The model can also determine the optimum magnet pole-arcs for each segment and the optimum airgap spacing between the segments. The analytical model is then applied to evaluate the performance of a three-phase, 12-slot/8-pole, surface-mounted PMSM having two segmented magnets per pole with RM. With design objective for minimum cogging torque and minimum total harmonic distortion in phase back-emf waveforms, we obtain that the optimum settings are 147.6° elect. for magnet segment pole-arc and 11.2° elect. for airgap spacing between the magnet segments. These analytical results are further compared and validated by 2-D finite element analysis (FEA). Additionally, we also compare the results with those from the optimum magnet pole-arc of one magnet segment per pole machine. It is observed that the cogging torque and total harmonic distortion THDv of the phase back-EMF are significantly reduced by 89% and 25%, respectively, with constraint and assumption that both machines utilize similar total magnet volume.
ANALYTICAL METHOD USING VIRTUAL PM BLOCKS TO REPRESENT MAGNET SEGMENTATIONS IN SURFACE-MOUNTED PM SYNCHRONOUS MACHINES
2017-06-10
PIER B
Vol. 76, 1-22, 2017
download: 324
A Generalized Hybrid Method for Electromagnetic Scattering Analysis of Multiple Objects
Quang M. Nguyen and Ozlem Kilic
We propose a generalized hybrid method to achieve time efficient and accurate solutions for electromagnetic scattering and radiation problems involving complex scenes with multiple objects. The method utilizes frequency domain solutions, and is based on dividing the original computational domain into smaller sub-domains. Each sub-domain is first solved independently, then the interactions between the sub-domains are accounted for through an iterative procedure. The main difference of the proposed hybrid method in comparison with the current hybrid methods or the domain decomposition methods available in the literature is that the proposed method allows users to have the freedom to choose from a variety of techniques for each sub-domain; such as integral equation (IE), analytical and asymptotic methods that suit the problem at hand best. Current hybrid or domain decompositions methods rely on a predetermined combination of numerical techniques. This flexibility in the choice of the method employed for each sub-domain in the generalized hybrid method is achieved by creating an interface capable of interacting between the different sub-domains properly. Furthermore, the method renders to parallel implementation as each sub-domain is solved independently. The hybrid method in its current state can be applied to two different scenarios: (i) multiple non-touching homogeneous objects, and (ii) inhomogeneous objects. Numerical examples of various combinations of IE, analytical and asymptotic methods are presented to validate the accuracy and the robustness of the generalized hybrid method.
A GENERALIZED HYBRID METHOD FOR ELECTROMAGNETIC SCATTERING ANALYSIS OF MULTIPLE OBJECTS