| Abstract: | The dynamic analysis of discontinuities in printed circuits has been performed using the mode matching technique. This study concerns the open end of microstrip lines and suspended microstrip lines. The fields on either side of the discontinuity are described by means of the continuous (radiated and evanescent) and guided modes of the structure. The conditions of continuity of the electromagnetic fields are then applied in the plane of the discontinuity. By taking into account the relations of orthogonality of the modes of the same region, a system of coupled Fredholm integral equations is obtained and solved by the iterative method of Neumann's series. The study calls for the use of the continuous spectrum of microstrip lines, which can be obtained analytically only after a great amount of calculation and CPU time. Thus, the first approach consists in neglecting this continuous spectrum. This gives accurate results for the reflection coefficient but it is not sufficient for the derivation of the radiation pattern. So, two simple models for the continuous spectrum, both based on the physical behaviour of such discontinuities, are considered and discussed. © 1997 John Wiley & Sons, Ltd. |
