Loop/tree implementation of AIM for microstrip models of complex geometry and minute features

Loop/tree basis functions have been used to resolve the short coming of the MoM approximation of EM integral equations, which is the so-called low frequency breakdown. The miniaturization and high-density integration of electronic devices have led to new classes of RF/microwave passive components charactered by increasing geometric complexity and numerous minute features. Analysing these structures, we face with the same problem as the low frequency case, which occurs when the wavelength becomes substantially larger than the characteristic size of the grid. To solve multiply-connected and self-intersecting microstrip models, we develop a new way to construct the loop-tree transform matrix and adapt the adaptive integral method. This operator results in a well-conditioned matrix, and accelerates the calculation.