ACES Publication Search





There are 29 search results for:



Title: ACES Journal June 2019 Cover
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 2237 KB

Title: ACES Journal June 2019 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 9510 KB

Title: ACES Journal June 2019 Full
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 31579 KB

Title: Parallel Integral Equation Based Non-overlapping DDM for Fast Solving Electromagnetic Scattering Problems with Changeable Parts
Abstract: In this paper, a parallel non-overlapping domain decomposition method (DDM) using electric field integral equation (EFIE) is proposed for fast and accurate analysis of electrically large PEC objects with changeable parts in the condition of limited resources. The approach has considered that there are null fields as well as electric current inside a metal object in the original problem, then a novel transmission condition similar to an absorbing boundary is adopted, hence the continuity of electric currents is enhanced and the convergence is further improved in the outer iterative procedure. Moreover, the coupling between different subdomains is calculated in the manner of near field to avoid the storage of the mutual impedance. Some numerical examples are given to demonstrate the efficiency and stability of the proposed method.
Author(s): Z. Gu, X. Zhao, C. Zhai, Z. Lin, Y. Zhang, Q. Zhang
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 2056 KB

Title: A Divergence-free Meshless Method for Transient Vector Wave Equations
Abstract: With the implementation of the vector radial basis function (RBF), which is theoretically divergence free, we propose a meshless method for solving the transient vector wave equation. Unlike the conventional radial point interpolation meshless (RPIM) method based on the scalar RBF that solves electric field and magnetic field components separately with scalar wave equations, the proposed method solves the vector wave equation directly. Therefore, the long-existing technical challenge of the source in the traditional RPIM method is resolved due to the direct solution of the vector wave equation. In addition, the stability condition of the proposed method is presented. At last, several numerical experiments are conducted to validate the accuracy of the proposed solver.
Author(s): S. Yang, D. Su, Z. Chen
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1800 KB

Title: A Hybrid Approach for Rapid Computation of Monostatic Radar Cross Section Problems with Characteristic Basis Function Method and Singular Value Decomposition
Abstract: Characteristic basis function method (CBFM) is one of the effective methods to analyze wide-angle electromagnetic scattering characteristics of objects. In the general CBFM, a mass of plane waves is required to construct the characteristic basis function (CBFs) for a large-scale target resulting in a large number of CBFs. Furthermore, the accuracy cannot be further enhanced via general method by increasing the number of incident plane waves to obtain adequate CBFs. In order to alleviate these problems, a hybrid approach is proposed for fast computation of monostatic radar cross section of objects. The proposed method applies the singular value decomposition to compress the excitation matrix and introduces a new method to construct the CBFs considering the mutual interaction among blocks. Under such circumstances, the number of matrix equation solutions and the number of CBFs are both significantly reduced. Thus, the time of constructing CBFs and the complexity of reduced matrix both are reduced. Numerical examples verify and demonstrate that the proposed method is credible both in terms of accuracy and efficiency.
Author(s): W. Nie, Z. Wang
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1573 KB

Title: Effective Modeling of Tunable Graphene with Dispersive FDTD - GSTC Method
Abstract: We propose an effective method of dispersive finite difference time domain-generalized sheet transition conditions (FDTD-GSTCs) for the modeling of electromagnetic fields from tunable graphene with nearly zero thickness. To model the tunable graphene effectively, the susceptibilities are introduced instead of its physical structure, which can be extracted from reflection or transmission coefficients. In order to model the graphene in broadband, a dispersive FDTD-GSTC method is introduced by fitting the susceptibilities with respect to frequencies with the complex-conjugate poleresidue (CCPR) pairs. Numerical results demonstrate the validity of the proposed method.
Author(s): X. Du, H. Yu, M. Li
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 2104 KB

Title: Efficient Leapfrog SF FDTD Method for Periodic Structures at Oblique Incidence
Abstract: This paper presents an efficient explicit leapfrog implementation of the split-field (SF) finitedifference time-domain (FDTD) method for solving problems of the oblique incident plane wave on periodic structures. Firstly, by splitting only one field component, the additional time derivative terms of transformed Maxwell’s equations can be eliminated. Then, by applying Peaceman–Rachford scheme, one-step leapfrog scheme and Sherman-Morrison formula, the proposed SF method is implemented in a much simpler explicit scheme than traditional SF FDTD method and some unconditionally stable methods. Furthermore, the stability condition of the proposed method is weaker than traditional SF FDTD method. The accuracy and efficiency of this method are verified by numerical results.
Author(s): Q. Lei, L. Shi, J. Wang, H. Chen, S. Fu
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1626 KB

Title: Numerical De-embedding of Periodic Guided-wave Structures via SOL/SOC in FEM Algorithm
Abstract: This paper presents a 3D full-wave finite element method (FEM) combined with short-open-load (SOL) and short-open calibration (SOC) technique. Due to the effective calibration of the port discontinuities between the feeding line and periodic structure, both SOL and SOC can successfully extract the intrinsic unite-length parameters, i.e., complex propagation constants and effective characteristic impedances. Distinctively, the SOL can be easily implemented with the commercial software such as Ansys HFSS, which is widely applicable for various kinds of periodic structure. More importantly, the SOC incorporated within the FEM algorithm intrinsically reduces the requirement of the load standard in SOL. Also, the SOC in FEM will be independent with the absorbing boundary condition at the port. And the port information such as characteristic impedance and propagation constants at the designated port will not be required in advanced, thereby allowing the arbitrary implementation of non-uniform feeding structures. In order to demonstrate the efficiency and accuracy of our proposed approaches, two numerical examples are given out for verification.
Author(s): Y. Li, D. Xie, L. Zhu
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1406 KB

Title: On the Application of Continuity Condition in the Volume-Surface Integral Equation for Composite Closed PEC-Electrical Anisotropy Objects
Abstract: The validity of the use of continuity condition (CC), combined with the volume-surface integral equation (VSIE), is studied when it is explicitly enforced on the closed perfect electric conductor (PEC)-electrical anisotropy interfaces. It is found that if the standard magnetic field integral equation (MFIE) is involved in the VSIE to model the closed PEC surfaces, the solution might be inaccurate, especially when the CC is enforced. The reason for this phenomenon is discussed, and two previously reported approaches are adopted to improve the accuracy of MFIE. Numerical results show that whether the CC is enforced or not, the improvement of the MFIE will result in more accurate VSIE solution.
Author(s): J. Liu, Z. Li, J. Song, L. Luo
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1621 KB

Title: A Fourier Split-Step Based Wide-Angle Three-Dimensional Vector Parabolic Wave Equation Algorithm Predicting the Field Strength Over Flat and Irregular Forest Environments
Abstract: This paper provides the analysis of radio wave propagation prediction over flat and irregular forest environments. A three-dimensional vector parabolic wave equation (3DPE) method is used to calculate the field strength due to the forest on a lossy ground. Forest terrains are equivalent to a series of absorbing blocks arranged along the direction of propagation. Under the assumption of forwarding propagation, a 3DPE is derived and the Fourier split-step based PE (SSPE) method is adopted to march the potentials from one aperture plane to the next. A Tukey window function is used to attenuate the fields smoothly at the upper boundary without reflections. Finally, the simulation results are compared with the analytical methods presented in the literature. The simulation results have shown the validity of the proposed algorithm.
Author(s): H. F. Rasool, X.-M. Pan, X.-Q. Sheng
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1434 KB

Title: Fast ISAR Imaging based on High Frequency Scattered Fields from Quadratic Patches
Abstract: This paper implements the two-dimensional (2D) non-uniform Inverse Fast Fourier Transformation (NUFFT) to Inverse Synthetic Aperture Radar (ISAR) imaging. The complexity of two-dimensional NUFFT is O(MNlog2MN), which is better than direct calculation with complexity O(M2N2) and has controllable interpolation error. As for the echo scattered fields acquisition with respect to multiple frequencies and azimuth angles, we use physical optics (PO) method based on quadratic discretization to reduce the patch number to two orders of magnitude, compared with planar discretization. Three examples prove that the 2D imaging process has nearly equal accuracy and higher efficiency.
Author(s): A. W. Wu, Y. M. Wu, Y.-Q. Jin, H. Yin, C. Fang, N. Zhang
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 2918 KB

Title: Design of Defective EBG Structures for Dual-Band Circular Patch MIMO Antenna Applications
Abstract: Usually, a reasonably designed electromagnetic band-gap (EBG) structure can reduce the surface wave of an antenna. However, it may take a long time to design. In this paper, a dual-band circular patch multiple-input multiple-output (MIMO) antenna on an EBG surface is proposed. Defects are simply introduced into rows and columns of the EBG cells. In this way, the band-gap bandwidth (BG-BW) of those cells can be as large as 29.2%, which enables the EBGs can cover two frequency bands with a large interval, and to generate over 25 dB isolation between the antenna elements, as well. The measured results show that the proposed antenna, incorporating defective EBGs, operates at 5.71-5.97 GHz and 6.31-6.54 GHz. The -10 dB impedance bandwidth of the antenna is extended by 28.9% and 27.8% at the low and high frequency band. In addition, its gain is enhanced by 5 dB and 6.9 dB, and its back radiation decreased by 15 dB and 10.3 dB at the resonant frequencies of 5.75 GHz and 6.44 GHz, respectively. The proposed design may have many applications in communication systems.
Author(s): X. Zhang, Y. Chen, H. Ma, L. Li, H. Xu
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 2082 KB

Title: High-gain Wideband Fabry-Perot Resonator Antenna Based on Single-layer FSS Structure
Abstract: In this paper, a wideband Fabry-Perot (FP) resonator antenna is designed based on single-layer frequency selective surface (FSS) structure. The antenna adopts a single-layer complementary circular FSS structure as the partially reflecting surface (PRS) of Fabry-Perot resonator antenna to improve the gain. The wideband slot-coupled patch antenna is used as the source. The proposed FSS maintains a positive slope reflection phase gradient in the band of 10.3-16.0 GHz, which satisfies the realization conditions of the wideband Fabry-Perot resonator antenna. The measured results show that the 10-dB impedance matching bandwidth of the proposed Fabry-Perot resonator antenna covers 11.99-15.54 GHz (25.8%), the maximum gain is 13.16 dBi at 14.2 GHz, and the 3-dB gain bandwidth is 26.1%. The measurement results verify the feasibility of the design method.
Author(s): Z. Liu, S. Liu, X. Kong, Z. Huang, X. Zhao
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 2000 KB

Title: Design of a W-band Dual-polarization Monopulse Reflector Antenna
Abstract: This paper introduces a W-band dualpolarization reflector antenna which combines one dualpolarized transmit-receive SUM channel and two singlepolarized DIFF receiving channels. The feed of the antenna consists of four OMTs (Orth Mode Transducer) to realize dual-polarization monopulse angle measurement. Four horns of the feed are combined into one radiation aperture by a coupled retracted structure to decrease side-lobes. The SUM beam gain of the proposed antenna is over 41 dBi and the aperture efficiency of 60% is achieved, cross-polarization level is better than –43 dB. The first sidelobe level is better than -30dB. The nulldepth is better than -20dB.
Author(s): W. Tan, H. Luo, G. Zhao
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1384 KB

Title: Design and Implementation of High Performance UWB Horn Antenna
Abstract: Broadband horn antennas have been widely used in radar and communication systems. They have also been added to various state-of-the-art control systems to perform EMC measurements. EMC measurements traditionally use standard gain horn antennas for many practical reasons like needing 8 standard antennas to test a wide range of frequencies (e.g., 0.75-18 GHz). This results in space efficiency reductions (e.g., the anechoic chambers efficiency is reduced). To solve this problem, an ultra-wideband (UWB) double-ridged horn antenna is designed and tested in this study. The antenna exhibits improved gains, VSWRs, and radiation patterns. Radiation patterns maintain a single main lobe across the full band. This signifies that the designed antenna can fulfill the desired higher demands. We have fabricated the antenna and it has been applied to many related fields.
Author(s): N. Hu, W. Xie, J. Liu, S. Liu, L. Zhao, C. Yuan
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1471 KB

Title: Investigation of the RCS for Finite Bandpass Frequency Selective Surface
Abstract: Frequency selective surface (FSS) with finite size behaves differently compared to an ideal infinite one, due to the influence of fringe effect, while there exist little study concerning this subject. RCS radiation can serve as a critical indicator of the FSS performance which can quantitatively reveal the mechanism of the fringe effect. This paper presents the study of RCS for FSS with finite structures. RCS for different sized FSS with different configurations under plane wave illumination are studied qualitatively. The result reveals the frequency selectivity and fringe effect of finite FSS. Quantitative functional relations between fringe effect and dimension of FSS are first summarized for monolayer FSS. A new case is then picked and tested to verify the validity of the functional relations. The relations are also extended to multilayer FSS. It turns out that the relations are general properties of finite FSS excited by plane waves.
Author(s): C. Fang, X. Ye, Y. Zhang, Q. Wang, J. Zhao, N. Zhang, H. Jiang, C. Jin, M. Bai
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1696 KB

Title: Reduction of Mutual Coupling for Broadband Vivaldi Antennas Using Characteristic Modes Analysis and Lumped Loads
Abstract: A method to reduce mutual coupling for broadband Vivaldi antennas is presented in this paper. Theory of characteristic modes is used to analyze the surface currents on the Vivaldi antennas which may contribute to mutual coupling, and inductive loads are used to suppress these modes. Mutual coupling between adjacent Vivaldi antennas is reduced by 10~20 dB on average in a wide bandwidth. Three configurations, including the classical design, design with slot, and design with inductive loads are studied. Numerical and experimental results are presented to verify the effectiveness of this method, which ensures that the method has very little influence to normal operation of Vivaldi antennas.
Author(s): Z. Ma, Q. Wu
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1675 KB

Title: Development of Microstrip Structure and Microstrip Sensor for Measurement of Transient Electromagnetic Pulse
Abstract: In this paper, a type of microstrip structure and sensor based on the microstrip structure are designed, fabricated and tested for the measurement of transient electromagnetic pulse. The voltage on the terminal load of microstrip line illuminated by a plane wave is analyzed, and a method of recovering the incident electric field is presented to recover the transient electromagnetic pulse by numerical processing. The proposed microstrip structures are set on the shielding boxes. The start of microstrip structure 1 without substrate is short circuited, and the start of microstrip structure 2 with substrate is matched. The induced voltage is acquired from the ends of microstrip structures. The simulated results and the measured results verify that the microstrip structures can be used to measure the transient electromagnetic pulse with rise time of ≥ 1 ns. The simulated results show that the microstrip structures have wide bandwidths of 1.5 GHz and 2.5 GHz, respectively. In addition, the simulated effective heights show consistency with the measured effective heights. The microstrip sensors, built by adding the electro-optical conversion modules into the shielding boxes, have good fidelity and can be used to measure high-altitude electromagnetic pulse (HEMP).
Author(s): J. Wei, S. Zhang, Z. Liu, Y. Yan, T. Jiang, F. Huang
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1684 KB

Title: Field-to-Wire Coupling Model for Wire Bundles with Strongly Non-uniform Path
Abstract: This paper presents a field-to-wire coupling model for wire bundles with strongly non-uniform path. Previous studies on multi-conductor transmission lines (MTL) are mainly confined to uniform or weakly nonuniform path, which is sometimes not the case in practice. In this paper, the external and internal characteristics of the wire bundle are decomposed by a mode transformation method, of which the advantage is the transformation matrices do not vary with the nonuniform path. The external characteristics correspond to common-mode (CM) components, modeled as an equivalent single wire running in the same path with the bundle above the reference ground. The internal characteristics correspond to differential-mode (DM) components, modeled as a uniform MTL system composed of the original wires in the bundle. In this way, the effects of the non-uniform path and the external field only exist in the CM model. Mode conversion caused by the dielectric coating and terminals is modeled with equivalent circuits. The proposed model is validated with a bundle of curved wires above a PCB board.
Author(s): X. Song, D. Su, J. Wang, B. Li
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1441 KB

Title: Necessity of Charge Measurement for Radiation Evaluation of Transmission Lines
Abstract: This paper attempts to arouse people’s attention to charge measurement in electromagnetic compatibility, especially when evaluating the radiation of transmission lines (TLs). Usually the total current (or common-mode current) is supposed to represent the potential radiation of a TL system. However, it is proved that the measurement of charge, which is the dual source quantity of current, is also necessary to evaluate radiation in this paper. Only when the current and charge are both obtained, the radiation field could be determined accurately. First of all, it is pointed out that charge information could not be properly obtained by current measurement. Although charge could be derived from current theoretically, the error transferred from current to charge could be great for measurement. Then, the error transferred from current to near field (which reflects the charge distribution) is studied by simulation of a typical TL case. And it is proved that such error could be reduced effectively if current is modified by charge. In addition, another important reason for charge measurement is given as limited measurement points, since the standing waveform on TLs cannot be determined by current only. Finally, a possible method for charge measurement is proposed.
Author(s): B. Li, X. Song, D. Su
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 2217 KB

Title: A Low-loss Wideband Filtering Coupler with Patterned Substrate Integrated Suspended Line (SISL) Technology
Abstract: A wideband filter-integrated coupler has been presented using the substrate integrated suspended line structure with patterned substrate. This coupler is composed of a two-line coupled line, two variant coupled lines, and four three-line coupled lines at each port. The SISL structure is composed of five print circuit boards, connected together by metal via holes. There is a hollowed substrate between two air cavities to reduce the loss. For further explanation, two wideband filtering SISL couplers operating at different operating frequencies with equal/unequal power divisions are designed and simulated, of which a specific coupler working at 1.66 GHz with a relative bandwidth of about 52.56% is fabricated and measured. The experimental results agree well with the theoretical and simulation ones. This proposed coupler has many advantages such as selfpackaged, low loss, filter integration, arbitrary power division ratio, and inherent DC-block function.
Author(s): L. Ma, Y. Wu, M. Li, W. Wang, Y. Liu
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1593 KB

Title: A Study on Equivalent Circuit Model of RF Discharge Based on Multi-Physics Field
Abstract: Belongs to EMC problems, the equivalent circuit model of RF discharge is studied. By establishing the correlation between circuit parameters of equivalent circuit and plasma characteristics, this paper conducts a brief analysis on the RF discharge mechanism with different frequencies.
Author(s): X. Fu, F. Dai, R. Hu
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1595 KB

Title: A Novel Classification Method Based on Adaboost for Electromagnetic Emission
Abstract: Abundant characteristics information of equipment or systems could be obtained from electromagnetic emission data. In this paper, those typical characteristics, like harmonics, damped oscillations, of electromagnetic emission are classified via the adaptive boosting (Adaboost) algorithm and they are validated through measurement results. Based on the “basic emission waveform theory”, three types of the basic fundamental elements, characteristics-harmonic, narrowband and envelope-of complex emission in frequency domain, are considered in our proposed method. By taking weights combination patterns to effectively improve the classification performance of a single classifier, quite high classification accuracy could be achieved by Adaboost algorithm in our simulations. In our study, 100% precision classification accuracy of three types of characteristics could be obtained using Adaboost with 13 decision tree weak-classifiers. Compared with other classification methods, the Adaboost algorithm with decision tree weak-classifier used to classify typical characteristics of electromagnetic emission is the most accurate. At the same time, it is very effective to process the measured data. Only through the classification of multiple emission signals can identification and positioning of electromagnetic interference sources further.
Author(s): J. Nie, S. Yang, Q. Ren, D. Su
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1973 KB

Title: Feasibility Analysis of the Installation of a Guided-Wave HEMP Simulator in an Electromagnetic Shielding Room
Abstract: Field strength, waveform and uniformity are crucial to the validity of high-altitude electromagnetic pulse (HEMP) radiation sensitivity test (RS05/RS105) for large transient field facilities which are placed in expensive semi-anechoic chambers (SAC) usually. In this paper, we present a type of space requirements of those large transient field facilities installations in cheaper electromagnetic shielding room (ESR) by quantitative simulation analysis of the crucial factors. The field uniformity and the accuracy of guided-wave EMP simulator (GWES) in a SAC are verified by numerical cases and experiments. Time domain finite integral method (FIT) is employed to compute field data and singular value decomposition (SVD) technique has been used to extract the higher order modes (HOM). Based on the validated model, feasibility of GWES installation in an ESR was analyzed. The minimum space requirement of GWES installation has been obtained through optimization.
Author(s): Y. Li, D. Su, S. Cui, W. Li
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1497 KB

Title: Frequency Response of Electromagnetic Wave Propagation in Power Tracks
Abstract: Previous investigations into the on-chip power distribution network (OCPDN) have focused on low frequency ranges. This study analyzes the highfrequency behavior of OCPDNs, where the wavelength approaches the dimension of the OCPDN and the track structure in the OCPDN. A theoretical model based on transmission line theory with common mode and differential mode analysis is established. The model shows that the power tracks can block the propagation of electromagnetic waves in certain frequency ranges and that wide stopbands exist. Full wave simulation based on (HFSS) is performed to verify the model. The simulation results match the theory, confirming the predicted behavior of the power tracks. Measurements are performed on prototype power tracks and the results are again consistent with the theory. The behavior of the power tracks shown here provides important information for the design of integrated circuits for millimeter-scale wave communications.
Author(s): C. Wang, T. Su
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 2529 KB

Title: A New Time-of-Flight Extraction Method for Narrowband Lamb Wave in Metallic Plate
Abstract: Lamb wave is potential to evaluate the health state of plate-like structures in nondestructive testing. However, the dispersive and multimodal properties of Lamb wave bring negative effect on the extraction of time-of-flight (TOF) which is important information to map the structure. This paper proposes a new method based on the ridge analysis to accurately extract the TOF of narrowband Lamb wave. The method establishes the ridge curve in the time-frequency domain and then, the TOF of corresponding frequency can be obtained utilizing the time information in the ridge. An experiment system using the electromagnetic acoustic transducer is established on the steel plate to verify the performance of the proposed method. The results show that the ridge analysis method has higher accuracy than the traditional Hilbert Transform method. Furtherly, the sensitive analysis proves that the proposed method owns high stability and strong robustness.
Author(s): Z. Wang, S. Huang, Q. Wang, S. Wang, W. Zhao
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1583 KB

Title: Hybrid Plasmonic Waveguiding Model in a V-shaped Silicon Groove
Abstract: A modified V-shaped silicon groove waveguide, embeded with metal nanowire,which is coated with a low refractive index layer was proposed. Finite element method (FEM) is used to numerically simulate the characteristics of the hybrid plasmonic mode at the wavelength of 1550nm. The simulation results show that the hybrid plasmonic mode can be confined to the dielectric layer on the surface of the metal nanowire. Meanwhile, factors on the modal properties are analyzed. Low loss and strong mode confinement can be realized by adjusting the size of the dielectric and metal nanowires as well as the angle of the V-shaped groove. The overall performance of the proposed model is superior to that of traditional hybrid plasmonic waveguides.
Author(s): X.-J. Kuang, Z.-X. Huang, X.-Y. Cao, M. Kong, J. Shen, X.-L. Wu
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1668 KB

Title: A Study on the Propagation Characteristics of AIS Signals in the Evaporation Duct Environment
Abstract: The propagation characteristics of signal of the Automatic Identification System (AIS) in the evaporation duct environment over the sea surface are investigated by using the parabolic equation method. The parabolic equation method has excellent stability and accuracy in solving the computational problem of electromagnetic wave propagation under different atmospheric conditions and it is probably the most suitable for the purpose of analyzing AIS signals. The propagation of AIS signals in air is determined by the variation of the refractivity with height. For AIS transmission, ducting propagation may be the most important propagation mechanism. The propagation loss of AIS signals in the evaporation duct is calculated and compared with that for the case of the standard atmosphere. In order to demonstrate the effect of evaporation duct on the propagation of AIS signals more intuitively, propagation loss versus range for three typical AIS links and the receiver height versus propagation loss under different atmospheric conditions are analyzed in details. The simulation results show that the evaporation duct has little influence on the AIS system.
Author(s): W. Tang, H. Cha, M. Wei, B. Tian, Y. Li
File Type: Journal Paper
Issue:Volume: 34      Number: 6      Year: 2019
Download Link:Click here to download PDF     File Size: 1460 KB