Research on the Accurate Evaluation of Higher Order Nearly Singular Integrals Based on the Improved Double-Arctan Transformation
REN Yi1, LUO Wei1, HU Hao2
1. Chongqing University of Posts and Telecommunications, Chongqing 400065, China;
2. Beijing Institute of Control and Electric Technology, Beijing 100038, China
Abstract:The accurate evaluation of higher order nearly singular integrals is one of the key technologies in accurate simulation by electromagnetic surface integral equations (SIE).However,the present methods mainly focus on low order nearly singular integrals for the planar element modeling,rather than on 3-order nearly singular integrals in higher order geometry modeling.Based on the former research of the Double Arctan-Transformation (DAT),the Improved Double Arctan-Transformation (IDAT) is proposed to improve the stability and accuracy of the nearly singular integrals with singular kernel RR/R5, R/R4 and 1/R3 for higher order geometry modeling.Specifically,the exponential transformation is utilized to stabilize the integrals when the field points are extremely close to the source surface.Furthermore,the shape-function transformation is adopted to stabilize the integrals when the projection point approaches to the border of source surface.The proposed IDAT is also effective for the lower orders of the nearly singular integral kernels.With theoretical analysis and typical testing cases,the accuracy and stability performance of IDAT is fairly evaluated.
任仪, 罗伟, 胡浩. 基于改进型双正切变换的高阶近奇异性精确积分方法研究[J]. 电子学报, 2020, 48(10): 1873-1882.
REN Yi, LUO Wei, HU Hao. Research on the Accurate Evaluation of Higher Order Nearly Singular Integrals Based on the Improved Double-Arctan Transformation. Acta Electronica Sinica, 2020, 48(10): 1873-1882.
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