Transmission line model for longitudinal slot dielectric-filled waveguide

The slot waveguide finds many applications such as radar and communication systems, which require narrow-beam or shaped-beam radiation pattern. Resonant arrays have the added advantage of presenting very low transmission loss and low cross-polarization, typically in millimeter waves. Others advantages are the low profile, the compactness and the light weight of the antenna. To improve this one and to reduce the cost of the antenna, technologies have been developed, based on foam metallization. So the waveguide is filled with dielectric, which is taken into account in the analysis. Theoretical results using this method show a good agreement with both CST Microwave Studio ones and measurements obtained by experiment in the laboratory. Offset slot effects and waveguide permittivity are taken into account. This method, based on the lossy transmission line, is very flexible and can be extended to various shapes like tilted slot or transversal slotted waveguide on the broad face or even in narrow wall of the waveguide. However the most interesting application may be the implementation of the components model on the method for active antenna, such as scanning beam antennas.