各向异性阻抗劈的绕射研究对雷达探测、电波传播和高频天线设计等方面有着重要的意义。当平面波照射在各向异性阻抗表面上时,可能激励起导波模形式的表面波,在表面波的传播过程中,若遇到几何参数或者物理参数不连续的目标(例如劈边)则会产生绕射场。考虑到斜入射情况下电场与磁场的耦合,在一致性几何绕射理论(uniform geometrical theory of diffraction,UTD)框架内应用摄动原理,以及Van der Waerden方法得到斜入射情况下各向异性阻抗劈散射场中表面波的绕射场贡献。
In this paper,a new method for extracting the parameters of buried object is proposed.The center position and dielectric properties of 2-D buried object are estimated by means of a regression technique based on support vector machine(SVM).The proposed method,after a proper training procedure,is able to reconstruct the center position and dielectric properties of a buried object inside a given investigation domain.Numerical simulation results indicate that SVM-based approach shows higher accuracy than the back-propagation neural networks(BPNN) algorithm.
In this paper, an adaptive digital filter algorithm is presented to optimize the signal-to-noise ratio of an antenna array with multiuser signal inputs. These synchronous communication signals have constant envelope property and are transmitted through a Multiple-Input/Multiple-Output (MIMO) linear channel. This Multiuser Constant Modulus Algorithm (MU-CMA) using an antenna array can compensate for both Interuser Interference (IUI) and Intersymbol Interference (ISI). The method is derived by minimizing the cost function of the constant modulus signals as well as cross-correlations between them. The simulation result in this paper shows the performance of this algorithm.