Electromagnetic waveguide

An electromagnetic, EM, apparatus, comprising:

• a first portion comprising a first mating surface;
• and
• a second portion comprising a second mating surface configured to be disposed on the first mating surface of the first portion;
• wherein the first portion has an overall height H1, the first portion comprising:
• an open-top structure having an upper surface profile having at least one top-down cavity comprising air and having a depth d1 where d1<H1;
• wherein each of the at least one top-down cavity has corresponding side walls;
• wherein outer exposed surfaces of the at least one top-down cavity with the corresponding side walls comprises an electrical conductor;
• wherein corresponding ones of the at least one top-down cavity with the corresponding side walls forms a lower portion of an air waveguide, AWG;
• wherein the second portion has an overall height H2, the second portion comprising:
• a lower surface profile configured to mate with the upper surface profile of the first portion;
• an upper surface profile having a plurality of top-down recesses, each of the top-down recesses extending to a plurality of floors at a depth d2 where d2<H2;
• a plurality of bottom openings, each of the bottom openings separating a pair of floors among the plurality of floors;
• wherein each of the top-down recess is at least partially filled with a dielectric medium having a relative dielectric constant greater than that of air that covers a corresponding bottom opening among the plurality of bottom openings;
• wherein portions of the lower surface profile proximate each of the bottom openings comprises an electrical conductor and forms an upper portion of the AWG.