CAD of viahole fed planar antennas using space discretizing field solvers

In this contribution we investigate planar antennas which are coupled by viaholes to a microstrip feedline. This way a narrow bandwidth can be combined with a high efficiency of the antennas. Planar antennas are mostly simulated by using the method of moments or the integral equation method. However the efficiency of these methods is mostly restricted to the application on strictly planar structures. Some of the methods have been extended to the application on viaholes but the whole variety of structure details which can occur in antenna design can not be modeled easily. For applications at antenna structures including metalization thickness, viaholes and dielectric layers of finite size the computation effort of these methods increases. Space discretizing methods are not restricted in their efficiency to structure details of special shape. For that reason we investigate viahole fed planar antennas by using space discretizing field solvers like the Alternating Transmission Line Matrix method. Different field solvers are compared in a discussion with respect to efficient and flexible antenna modeling.