Science and Technology on Electromagnetic Scattering Laboratory

Beijing, China

Science and Technology on Electromagnetic Scattering Laboratory

Beijing, China
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Sheng J.,Science and Technology on Electromagnetic Scattering Laboratory | Ren H.-M.,Science and Technology on Electromagnetic Scattering Laboratory
ISAPE 2016 - Proceedings of the 11th International Symposium on Antennas, Propagation and EM Theory | Year: 2016

Aiming at the problem of the difficulty in the range alignment of HRRP because of more than one target in the window of radar image, this paper propose a alignment method for multiple targets in the target group by using an image segmentation method. First, we accumulate the HRRP of the target, and get the HRRP process diagram. By calculating the correlation coefficient between each frame of HRRP and the reference HRRP, the unaligned HRRP sequence is aligned roughly in frequency domain. After rough alignment, the image segmentation method is used to segment the range image of each target. In the end, the envelope alignment for the HRRP of each target is finished using the least entropy method. The algorithm is simple and fast, and can achieve a better alignment effect on multi object tracking. The effectiveness of the proposed method is verified by the analysis of the simulation data. © 2016 IEEE.


Zhang J.,Cisco Systems | He X.,Science and Technology on Electromagnetic Scattering Laboratory
IEEE Transactions on Antennas and Propagation | Year: 2017

Isorefractive material has some novel properties. We consider the case of a plane wave scattered by a circular cylinder located at a plane interface between isorefractive half-spaces. We mainly study the high-frequency asymptotic diffraction contribution extracted from the series' expression. We prove that the extracted asymptotic contribution conforms to the classical asymptotic diffraction theory. © 2017 IEEE.


Lin Y.,Science and Technology on Electromagnetic Scattering Laboratory | Guo L.,Science and Technology on Electromagnetic Scattering Laboratory
Proceedings of 2016 IEEE International Conference on Electronic Information and Communication Technology, ICEICT 2016 | Year: 2017

A discontinuous Galerkin integral equation domain decomposition method based on adaptive cross approximation (ACA) is presented. The CN/LT basis function is used for correctly representing the continuity of the induced current on the boundaries. ACA is used for accelerating the solving of the linear system. Several numerical examples are given to demonstrate the correctness and the effectiveness of the proposed algorithm. © 2016 IEEE.


Li L.-S.,Science and Technology on Electromagnetic Scattering Laboratory
Communications in Theoretical Physics | Year: 2016

We explore the tricritical points and the critical lines of both Blume-Emery-Grifnths and Ising model within long-range interactions in the microcanonical ensemble. For K = KMTP, the tricritical exponents take the values β = 1/4, 1 = γ- ≠ γ+ = 1/2 and 0 = α- ≠ α+ = -1/2, which disagree with classical (mean held) values. When K > KMTP, the phase transition becomes second order and the critical exponents have classical values except close to the canonical tricritical parameters (KCTP), where the values of the critical expoents become β = 1/2, 1 = γ- ≠ γ+ = 2 and 0 = α- ≠ α+ = 1. © 2016 Chinese Physical Society and IOP Publishing Ltd.


Cheng D.,Communication University of China | Cheng D.,Tianjin University of Technology and Education | Yin H.-C.,Science and Technology on Electromagnetic Scattering Laboratory | Zheng H.-X.,Tianjin University of Technology and Education
Journal of Electromagnetic Waves and Applications | Year: 2012

To investigate a compact dual-band bandstop filter (DBBSF), a defected microstrip structure is proposed in this paper. The filter is composed of a spur-line structure and a rectangle slot. Resonant frequencies and the bandwidths of the filter can be adjusted by changing the length of the slot. The frequencies of designed DBBSF are operated at 2.12 and 2.9 GHz. A fabricated sample has been tested to verify our design. Measured and simulated results are in good agreement. The proposed filter is much more efficient than other similar structures. © 2012 Taylor & Francis.


Zhang M.,Xidian University | Chen H.,Xidian University | Yin H.-C.,Science and Technology on Electromagnetic Scattering Laboratory
IEEE Transactions on Geoscience and Remote Sensing | Year: 2011

This paper is aimed at developing an applicable and feasible facet model, which formulation should be tractable and time saving for personal computers to take charge of the efficient evaluation on the complex reflective function of large-scope 2-D oceans, either in the monostatic or bistatic case. The sea surface is envisaged as a two-scale profile on which the long waves are locally approximated by planar facets. The microscopic profile within a facet is assumed to be represented by a set of sinusoidal ripple patches. The complex reflective function of each modified facet is evaluated by a modified formula of the original Bass and Fuks' two-scale model, in which the phase factor of each facet is with the capillary wave modification. Several examples with application to the frozen or time-evolving case are given to prove the implementation. © 2011 IEEE.


Jiang W.-Q.,Xidian University | Zhang M.,Xidian University | Wei P.-B.,Xidian University | Yuan X.-F.,Science and Technology on Electromagnetic Scattering Laboratory
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing | Year: 2014

The small slop approximation (SSA) is an accurate method to calculate the electromagnetic (EM) scattering properties of rough surfaces. However, its computational complexity restricts its application to smaller domains and there is always the need for speedup in very large cases using pure central processing units (CPUs) hardware. With the development of graphics processing units (GPUs), more processors are dedicated to perform independent calculations. In addition, NVIDIA introduced a parallel computing platform, compute unified device architecture (CUDA), which provides researchers an easy way to use processors on GPU. To calculate EM scattering properties on GPU, we reformulate the SSA method with CUDA to take advantage of GPU threads. Because each thread executes synchronously and deals with a corresponding point data of rough surface, the CUDA-based SSA method calculates faster than the pure-CPU equivalent. To overcome memory limitations, the data of large rough surface are stored on hard disk. Moreover, a subsidiary thread is used to deal with the process of data transmission between the memory and the hard disk and reduce transmitting time further. The factors, block size, data transfers, and register, are also discussed in the optimization of the CUDA application. Test cases running on a NVIDIA GTX 460 GPU indicate that two orders of magnitude speedup, including file input and output, is obtained with our new formulation. © 2008-2012 IEEE.


Li L.-S.,Science and Technology on Electromagnetic Scattering Laboratory | Yin H.-C.,Science and Technology on Electromagnetic Scattering Laboratory
Chinese Physics Letters | Year: 2014

We investigate the optical response of a metallic wire calculated from the classical electromagnetic theory. The Drude (local) approach is compared with the semi-classical hydrodynamical theory calculations that reveal the Fano-like resonances of subsidiary peaks originated from the nonlocality. The bulk plasma resonances containing the nonlocal effects could be depressed by increasing the dissipation, while the blue shift of the surface localized plasma resonances could be enhanced by increasing the Fermi velocity. © 2014 Chinese Physical Society and IOP Publishing Ltd.


Zhu Z.,Nanjing University of Aeronautics and Astronautics | Sun X.,Science and Technology on Electromagnetic Scattering Laboratory | Xue H.,Nanjing University of Aeronautics and Astronautics | Guo H.,Nanjing University of Aeronautics and Astronautics | And 3 more authors.
Journal of Materials Chemistry C | Year: 2014

Graphene is a highly desirable material for efficient electromagnetic wave absorption due to its strong dielectric loss and low density. However, the main drawbacks in pristine graphene, such as high dielectric constant and low permeability, inevitably limit its performance due to the poor impedance matching. In this paper, reduced graphene oxide-spherical carbonyl iron composites (RGO-SCI) have been successfully fabricated through a facile wet chemical method. As expected, an apparent improvement of impedance matching in electromagnetic wave absorption could be found through the combination of RGO and SCI. A carbon-bridge effect was adopted to explain the electromagnetic wave absorbing process, which is closely related to a cross-linked framework structure of as-synthesized composites. Besides, in the range of 7.79-11.98 GHz with the thickness of 3.0 mm, the RGO-SCI composites exhibited efficient electromagnetic wave absorption characteristics (RL < 10 dB) with a minimum reflection loss of -52.46 dB. This journal is © the Partner Organisations 2014.


Chen H.,Xidian University | Zhang M.,Xidian University | Yin H.,Science and Technology on Electromagnetic Scattering Laboratory
Progress in Electromagnetics Research | Year: 2012

A feasible simulator, of which formulation and mechanism should be simple and time saving, is developed in this paper to overcome the diffculties of prediction on the EM scattering from three- dimensional (3-D) electrically very large ship-sea models. The work in this paper is twofold. First, the sea surfaces are supposed to be a combination of many locally-tilted slightly rough facets with two-scale profiles. The radar return from each local facet is associated to a semi- deterministic scheme which is established by combining the geometric optics limit of Kirchho® Approximation (KA-GO) with the Bragg components of Bass-Fuks' two-scale model (BFTSM). Furthermore, we associate the complex reflective function of the respective facet by a so-called Phase-modified Facet Model (PMFM), in which the facet's phase is treated approximately as a combination of inherent part that follows a homogeneous random distribution and coherent part associated with the relative path-delay. Second, in companion with the semi-deterministic treatment of the sea scattering model, a hybrid approximate algorithm is proposed to deal with the composite scattering of electrically large ship-sea model, which is entirely evolved through facets (for the sea surface) and wedges (for the ship target). The method of equivalent currents (MEC) and a hybrid frame which combines the four path model (FPM) with the quasi-image method (QIM) are employed to calculate the scattering characteristics of the ship-like target and ship-sea interactions, respectively. The entire simulator is of comparatively significant computational effciency, and suitable for providing a preliminary prediction on the instantaneous complex reflective functions and normalized radar cross sections (NRCS) mean levels for electrically very large ship-sea model.

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