Full-wave analysis of dielectric-loaded waveguide slot antennas including internal and external mutual coupling

A hybrid full-wave technique is proposed to analyze the structure having two slots cut in the wall of a rectangular waveguide partially filled with a dielectric slab. Each slot element is decomposed into two parts: a dielectric-loaded waveguide T-junction and an open-ended waveguide. A four-port network is composed in the T-junction cascading and the internal mutual coupling between the two slots is included automatically. The external mutual coupling is calculated by a full-wave integration method. Combining the scattering parameters of the four-port network and the external mutual coupling solves the whole waveguide slot structure. Numerical results obtained by our hybrid method are presented and compared with simulated data by Ansoft´s HFSS. Good agreement is observed for all the cases considered.