Abstract: In one example embodiment, a high-speed transponder includes a printed circuit board having a set of coplanar high-speed traces, and a high-speed circuit and a package mounted to the printed circuit board. The package includes an outside housing and a second high-speed circuit positioned inside the housing. The high-speed transponder also includes a high-speed feed thru which includes an inside coplanar structure positioned inside the housing, a strip line structure positioned through the housing, and an outside coplanar structure positioned outside the housing. The second high-speed circuit is operably coupled to the inside coplanar structure, which is operably coupled to the strip line structure, which is operably coupled to the outside coplanar structure, which is operably coupled to the first high-speed circuit via the set of coplanar high-speed traces. The signal plane of the outside coplanar structure is flipped with respect to a signal plane of the inside coplanar structure.