A proper arrangement of the forked ends is given through analysing the working principle and characteristic of the slipper type universal coupling.

Coupling piece for joining two containers that are stacked one atop the other, arrangement of stacked containers, and method for joining stacked containers using coupling pieces of this type.

The results show that the two antennas of the overall arrangement perform simultaneously well in the cavity and the mutual coupling effect expands the bandwidth of the horizontal monopole.