Insertion loss for two microstrip ports coupled by proximity slots

A slot-coupled microstrip vertical interconnection was successfully used to interconnect two microstrip lines on two adjacent signal layers. The present study investigates an extension of this method, when two layers are separated by an air gap of a finite thickness h. Such a geometry implies a very short-range wireless link (slot-to-slot magnetic coupling). It may be of interest for high density three-dimensional microwave systems with rapidly replaceable components.