共查询到20条相似文献,搜索用时 0 毫秒
1.
Linear lumped loads in the FDTD method using piecewise linear recursive convolution method 总被引:1,自引:0,他引:1
Jung-Yub Lee Jeong-Hae Lee Hyun-Kyo Jung 《Microwave and Wireless Components Letters, IEEE》2006,16(4):158-160
This letter gives a new algorithm to include linear lumped elements into finite difference time domain algorithm. The proposed method can efficiently account for two-terminal networks made of several lumped elements. The piecewise linear recursive convolution (PLRC) technique is used to implement lumped loads into Yee cells. Using this method, it is possible to simulate equivalent circuits of terminations for microstrip structures, integrated circuits, or digital devices. The advantage of the PLRC technique is addressed and simulation results validating this method are presented. 相似文献
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New formulations based on the state-space approach are presented for implementing the anisotropic perfectly matched layer into the finite difference time domain (FDTD) algorithm. The formulations are simple and independent from the material properties of the FDTD computational domain. Numerical tests are included to validate the proposed formulations. 相似文献
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An FDTD formulation for dispersive media using a current density 总被引:7,自引:0,他引:7
Chen Q. Katsurai M. Aoyagi P.H. 《Antennas and Propagation, IEEE Transactions on》1998,46(11):1739-1746
A novel finite-difference time-domain (FDTD) formulation for dispersive media called the JE convolution (JEC) method is derived using the convolution relationship between the current density J and the electric field E. The high accuracy of the JEC method is confirmed by computing the reflection and transmission coefficients for a nonmagnetized plasma slab in one dimension. It is found that the new method has an accuracy comparable to the auxiliary differential equation (ADE) while having the same computational efficiency as the less accurate recursive convolution (RC) method. Numerical simulations also show that the JEC method exhibits significantly higher accuracy than the RC method in modeling wave attenuation inside the plasma 相似文献
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A new algorithm is presented for the finite difference time domain (FDTD) implementation of the anisotropic perfectly matched layer (PML) using the digital signal processing. The algorithm is based on modeling the anisotropic PML region as a set of infinite-impulse response (IIR) digital filters. The advantage of the proposed method is that it allows direct FDTD implementation of Maxwell's equations in the PML region. In addition, the formulations are implemented using D and B fields rather than E and H, and this allows the PML to be independent from the material properties of the FDTD computational domains. Numerical tests have been carried out in two dimensions to validate the formulations. 相似文献
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Piecewise linear implementation of nonlinear dynamical systems: from theory to practice 总被引:1,自引:0,他引:1
It is shown how to implement by a mixed-signal circuit a continuous-time dynamical system. The chosen case study is the Hindmarsh-Rose model of a biological neuron, but the design strategy can be applied to a large class of continuous-time nonlinear dynamical systems. The system nonlinearities are first approximated by using piecewise-linear functions and then digitally implemented on a field programmable gate array. The linear part of the system is completely analogue and is implemented by using operational amplifiers. Measurement results show that the circuit can reproduce the main dynamics of a biologically plausible neuron. 相似文献
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An efficient method based on the Z-transform theory and the D-H anisotropic perfectly matched layer formulations is presented for truncating general FDTD grids. The formulations are simple and independent of the material properties of the FDTD domain. Numerical examples for radiation and guided-wave problems are included to validate the proposed formulations. 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1979,67(8):1163-1165
A simple CAD model for avalanche photodetectors (APD) is developed. The model is based on a piecewise linear (PWL) approximation of the responsivity curve of the APD which may be obtained either from theoretical considerations or from terminal measurements. The model takes into account nonlinear effects in the design of APD optical receivers. 相似文献
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《Digital Communications & Networks》2018,4(2):98-105
Considering high-order digital modulation schemes, the bottleneck in consumer products is the detector rather than the modulator. The complexity of the optimal a posteriori probability (APP) detector increases exponentially with respect to the number of modulated bits per data symbol. Thus, it is necessary to develop low-complexity detection algorithms with an APP-like performance, especially when performing iterative detection, for example in conjunction with bit interleaved coded modulation. We show that a special case of superposition modulation, dubbed Direct Superposition Modulation (DSM), is particularly suitable for complexity reduction at the receiver side. As opposed to square QAM, DSM achieves capacity without active signal shaping. The main contribution is a low-cost detection algorithm for DSM, which enables iterative detection by taking a priori information into account. This algorithm exploits the approximate piecewise linear behavior of the soft outputs of an APP detector over the entire range of detector input values. A theoretical analysis and simulation results demonstrate that at least max-log APP performance can be reached, while the complexity is significantly reduced compared to classical APP detection. 相似文献
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把运用于处理各向同性媒质的分段线性递归卷积时域有限差分(PLRC-FDTD)方法进行拓展,用它处理任意磁偏角磁化等离子体的电磁问题,给出了该算法相应的递推计算公式,计算了任意磁偏角磁化等离子体平板对电磁波的反射系数和透射系数,算法结果与解析解相比吻合很好,从而验证了该算法用于任意磁偏角磁化等离子体的有效性和高精度.此外,当电磁波传播方向与外加磁场方向成任意取向时,反射系数和透射系数幅度的图像形状是相似的,都在等离子体频率处发生一个明显的突变. 相似文献
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Wang Shu Yao Tianren 《Electronics letters》1988,24(5):249-250
A linear convolution of two N -point sequences is computed by using N -point Fermat number transforms, so that the convolution length is doubled for a given modulo Fermat number. The algorithm is also suitable for other convolutional algorithms of number theoretic transforms 相似文献
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The authors present a new recursive algorithm for solving linear algebraic equations Ax=b. With this algorithm, the ith step recursion can find one solution of the first i equations; the unique solution of the total n equations could be found after the nth step recursion. Because of this recursive property, the algorithm can be used not only in solving ill-conditioned equations but also in recursive identification, signal processing and many other areas.<> 相似文献
14.
Lijun Xu Naichang Yuan 《Microwave and Wireless Components Letters, IEEE》2005,15(12):892-894
The JE convolution finite-difference-time-domain (JEC-FDTD) method is extended to the anisotropic magnetized plasma which incorporates both anisotropy and frequency dispersion at the same time, enabling the transient solution of the electromagnetic wave propagation in anisotropic magnetized plasmas. Two-dimensional JEC-FDTD formulations for magnetized plasma are derived. The back scattering radar cross section (RCS) of a perfectly conducting cylinder coated by a layer of magnetized plasmas is calculated. 相似文献
15.
A linear systolic array for recursive least squares 总被引:1,自引:0,他引:1
Classical systolic design procedures rely on linear or affine space-time transformations because of the well-understood properties of linear operations. In order to increase the efficiency of the final processor, various ad hoc manipulations applied to transformations that appeared to be nonlinear at the physical array level have been proposed. Folding is one of these possible transformations. The authors show that folding can actually be considered to be an overall linear procedure by artificially increasing the dimensionality of the dependence graph of the algorithm. A 1-D array for recursive least squares is also derived as an application of a systematic linear design procedure including folding 相似文献
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A perfectly matched layer (PML) absorbing material composed of a uniaxial anisotropic material is presented for the truncation of finite-difference time-domain (FDTD) lattices. It is shown that the uniaxial PML material formulation is mathematically equivalent to the perfectly matched layer method published by Berenger (see J. Computat. Phys., Oct. 1994). However, unlike Berenger's technique, the uniaxial PML absorbing medium presented in this paper is based on a Maxwellian formulation. Numerical examples demonstrate that the FDTD implementation of the uniaxial PML medium is stable, equal in effectiveness as compared to Berenger's PML medium, while being more computationally efficient 相似文献
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The electromagnetic propagation in dispersive magnetoplasma medium is modeled using the finite-difference time-domain (FDTD) method based on the exponential time differencing (ETD). The ETD schemes with first-order and second-order accuracy are presented. The ETD algorithm is accurate and efficient. The reflection and transmission coefficients of the magnetized slab for the right-hand circularly polarized wave are computed. 相似文献
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He R. Reed I.S. Trieu-Kien Truong 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2002,48(7):1835-1848
A recursive linear detection algorithm is proposed for the detection of signals from an asynchronous direct-sequence code-division multiple-access (DS-CDMA) communication system. This algorithm works for short as well as long codes. Under some reasonable conditions, this algorithm is proved to be stable and converges to the ideal decorrelating detector (IDD) with a sufficiently large memory length. The performance of the algorithm is analyzed in some detail. Upper and lower bounds for the bit-error probabilities are developed. It is demonstrated that the two bounds converge to the bit-error probabilities of the IDD as the large memory length increases. Simulation results show that the recursive detector proposed outperforms the truncated decorrelating detector with less memory and less computational complexity 相似文献
20.
Quadratic constraints on the weight vector of an adaptive linearly constrained minimum power (LCMP) beamformer can improve robustness to pointing errors and to random perturbations in sensor parameters. We propose a technique for implementing a quadratic inequality constraint with recursive least squares (RLS) updating. A variable diagonal loading term is added at each step, where the amount of loading has a closed-form solution. Simulations under different scenarios demonstrate that this algorithm has better interference suppression than both the RLS beamformer with no quadratic constraint and the RLS beamformer using the scaled projection technique, as well as faster convergence than LMS beamformers 相似文献