Fast Analysis of Microstrip Lines and Antennas in Cylindrical Multilayer Structures with Non-circular Cross Section

Kurzfassung

A technique is presented for the fast analysis of conformal microstrip lines and antennas, which is based on the discrete mode matching (DMM). This method has proven to be exceptionally effective for planar and cylindrical structures composed of numerous thin dielectric layers. The main advantage is that in contrast to several other simulation tools, the numerical effort is reduced, since the dimension of the structure in the direction of the layers is treated analytically by means of a full-wave equivalent circuit (FWEC) and thus need not be discretized. The computational domain may be enclosed with electric and magnetic walls or by using absorbing boundary conditions (ABCs) for problems involving radiation. This work describes an extension of the DMM that allows the analysis of electromagnetic problems in quasi-cylindrical coordinates. These are mainly cylindrical shapes with non-circular cross section. In this case, the radii of the interfaces are functions of the angle . Thus the usual spectral-domain formulation is not possible and the analysis involving the FWEC is performed in the space domain. The continuity conditions in the interfaces between the dielectric layers and on the metallizations are enforced by using suitable discretization schemes. For validation, some typical test structures are analyzed and the results compared with data obtained from literature or by using other simulation tools.