Integral equation solution for microstrip structures at low frequencies

Microstrip structures have been studied extensively using various types of full wave analysis techniques. However, these techniques have difficulties because they usually involve the solution of a very large system of linear equations. We successfully use a symmetric form of layered medium Green´s function to analyze the microstrip structure at low frequencies with the help of loop-tree basis functions, frequency normalization, and basis rearrangement. It converges quickly and no low-frequency breakdown occurs in the numerical computations. In the future, it will be capable of solving large scale problems. Numerical results are given for the current distribution pattern obtained due to a polarized plane wave impinging on a rectangular microstrip structure.