On the Transition from Ridged Waveguide to Microstrip

In conjunction with the transition from waveguide to microstrip via a rigded waveguide structure, two problems are investigated. The first one concerns the impedance of the ridged structure including a dielectric layer on the bottom of the waveguide, the second one the field discontinuity when an unloaded ridged waveguide with wide ridge is connected to a high ¿r microstrip of the same impedance but much smaller width.