An Improved MOM-GEC Method for Fast and Accurate Analysis of 2-D Planar Structures in Waveguides: Application to Planar Microstrip Antennas

This paper presents a new hybridization between MoM-GEC and a MultiResolution analysis (MR) which is based on the use of wavelets functions as trial functions. The proposed approach is developed to speed up convergence, alleviate calculation and then provide a considerable gain in requirements (processing time and memory storage) because it generates a sparse linear system. The approach consists in calculating the total current and input impedance on an invariant metallic pattern through two steps.The first one consists in expressing the boundary conditions of the unknown electromagnetic current with a single electrical circuit using the Generalized Equivalent Circuit method (GEC) and then deduce an electromagnetic equation based on the impedance operator [1,2]. The impedance operator used here is described using the local modal basis of the waveguide enclosing the studied structure. The second step consists in approximating the total current using orthonormal periodic wavelets as testing functions and the local modal basis of the waveguide as basis functions.The proposed approach allows fast calculation of such inner products through the use of the wavelets multiresolution (MR) analysis advantages, thus significantly reducing the required CPU-time for microstriptype structure analysis [3,4]. A sparse matrix is generated from the application of a threshold .A sparsely filled matrix is easier to store and invert [5,6]. Based on this approach, we study a 2-D planar structure including a step discontinuity. The obtained results show good accuracy with the method of moments. Moreover, we prove the considerable improvements in CPU time and memory storage achieved by the MR-GEC approach when studying these structures.