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One method can by Broyden-Fletcher-Goldfard-Shano (BFGS) algorithm and fractional fourier transform(FRFT) arrive at a reconstruction of a scene illuminated by SAR. Because there is only one argument (rotation angle α) in the BFGS process, it only needs several iterations to reach converge when processing one certain range bin and have much better impulse response than that of using matched filtering,...
In this article we present the simulation of bistatic inverse synthetic aperture radar (B-ISAR) imaging by exploiting back projection (BP) algorithm. We show the whole signal processing steps from coherent processing to final image forming in a certain given bistatic system setup. BP algorithm is utilized in the simulation and the results are shown and discussed to verify the validation of BP imaging.
In this talk, we will overview nonlinear plasmonic effects due to intrinsic, hydrodynamic metal nonlinearity, enhanced by sub-wavelength field confinement, interaction between plasmonic resonances and nonlocal effects. In particular, various nonlinear effects, such as nonlinear mode coupling, high-order harmonics and coherent supercontinuum generation will be discussed.
The research on orbital angular momentum (OAM) grows into a hot topic in electromagnetic and wireless communication field owing to its higher spectrum efficiency compared with the conventional multiplexing technology. This paper proposes a new way that the technology of OAM and circular polarization are combined into the design of array antenna. Eight circular polarized corner cutting micro-strip...
There could be all kinds of errors in the space-borne active array antenna because of its features such as highly integrated, complex configuration, strong mutual coupling and other factors. Obviously, these errors will affect the performances of array antenna. To address this issue, various methods have been proposed to calibrate these errors to guarantee the performance of the entire array.
A novel dual-band EBG-based Multiple-input multiple-output (MIMO) antenna system with high isolation performance for wireless local area network (WLAN) applications is proposed. The MIMO antenna comprises of two broadband printed slot antennas fed by a coplanar waveguide (CPW) feed line. When the antennas are placed at closer spacing, mutual coupling comes into existence deteriorating the performance...
We consider the accuracy and efficiency of surface integral equations, when they are used to formulate electromagnetic problems involving plasmonic objects at optical frequencies. Investigations on the iterative solutions of scattering problems with the multilevel fast multipole algorithm show that the conventional formulations, especially the state-of-the-art integral equations, can significantly...
A modified spectrogram approach is presented for the analysis of frequency modulated radar signals, taking the entropy as the evaluation criterion. The characteristics of spectrogram are firstly introduced. After the analysis of performance evaluation for time-frequency distribution, entropy is studied as a quantitative parameter for concentration and cross-term suppression. An improved spectrogram...
A balanced (Weston-type) absorber with both electric and magnetic conductances can be placed within the null field inside a scatterer, helping reduce interactions between pairs of opposing basis functions. The resultant MoM matrix is substantially thinned. Moreover, the annulled elements need not be computed, thereby reducing the matrix fill-up time.
Recently, we have developed the method of broadband Green's function with low wavenumber extraction (BBGFL) to investigate the problem of arbitrary shaped waveguides [1]. In the past, the Boundary Integral-the Resonant Mode Expansion (BIRME) [2, 3] method was applied to calculate the modes of an arbitrary shaped waveguide with a homogenous dielectric. In BIRME, a DC extraction is applied to remove...
It has been demonstrated in the literature on Characteristic Basis Function Method (CBFM) that higher compression rate can be achieved by using larger blocks while carrying out domain decomposition in the context of CBFM [1]. However, the increased degrees of freedom (DOFs) in large domains make the generation of the Characteristic Basis Functions (CBFs) very time- and memory-consuming for the following...
In this work we give a theoretical investigation on the near-field heat transfer between two graphene-hexagonal boron nitride (hBN) heterostructures. We found that the phonon-plasmon hybrid modes supported by the heterostructure could broaden the frequency and wavevector ranges for near-field photon transfer and lead to a rather high near-field heat transfer efficiency that is far stronger than the...
In the past few years there has been a great deal of interest in studying the efficient control of the interaction between quantum emitters (QEs) and nanostructures [1, 2]. Recently, we have investigated the interaction between quantum emitters and graphene wrapped nanowire (see Fig. 1(a)) by using a Green's function technique. The eigenmodes for the graphene wrapped nanowire at various Fermi levels...
The aperture integral equation (AIE) and method of moment (MoM) technique is proposed for analyzing the electromagnetic scattering properties of a finite perfectly conducting cone loaded with a slot. The solution allows us to deal accurately with slots of any shape. Two kinds of slots representing for electrical large and electrical small structure respectively, are considered in this paper. Bi-static...
While some logic analysis method has been used in the analysis of electronic commerce protocols for its simplicity, their lack of the ability in time description makes it helpless in the analysis of timeliness, which is one of the most important properties of electronic protocols. a novel logic is proposed by adding a simple time expression and analysis method to remedy the defect. Then a widely discussed...
Troposphere scatter communication is a kind of over-the-horizon communication depending on the medium inhomogeneity of the troposphere. By the acoustic wave, the inhomogenous layers with different dielectric constants can be formed artificially, which causes the coherent addition of reflection signal and enhances the radiation energy of the scattering wave. According to the turbulent flow theory of...
Effective thermal management is one of the most important issues for system-level integration technique. In contrast to traditional 2-D integrated system, complicated and multiscale components of the 2.5-D system significantly increase the modeling complexity. What is more, the super-linear relationship between temperature and power consumption further complicates thermal simulation. Among existing...
The integral equations (IEs) have demonstrated excellent potentials in analyzing large scale electromagnetic radiation and scattering problems. They stand out for properties like only discretization of the objects' surface, automatic satisfaction of the radiation condition, as well as no numerical dispersion. They are usually solved by the method of moment (MoM) following the Galerkin scheme. When...
In this paper, an efficient domain decomposition (DD) technique is introduced into the unconditionally stable finite-difference time-domain (FDTD) method based on weighted Laguerre polynomials (WLPs) for solving the far-field super-resolution focusing of time reversal (TR) waves. The WLP-FDTD method is very suitable for this multiscale problem due to the sub-wavelength array with some special microstructures...
Conventional coaxial relativistic backward wave oscillator (CRBWO) usually operates at the quasi-TEM mode, whose intense field mainly focuses on the slow wave structures (SWSs) surface. The intense relativistic electron beam (IREB) to stimulate high power microwave (HPM) is needed to pass through the SWSs surface closely so that intense beam-wave interaction can effectively occur. Such a structure...
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