Ultra wideband board-to-board transitions for stripline rf transmission lines

A radio frequency (“RF”) transmission line, comprising:

• a first printed circuit board that includes a first upper dielectric substrate, a first lower dielectric substrate, a first upper metal layer that is on an upper surface of the first upper dielectric substrate and including a first upper signal trace and a first upper ground plane, a first lower metal layer that is on a lower surface of the first lower dielectric substrate that forms a first lower ground plane, a first internal metal layer that is between the first upper dielectric substrate and the first lower dielectric substrate, the first internal metal layer including a first internal signal trace and a first internal ground plane;
• a second printed circuit board that includes a second dielectric substrate and a second upper metal layer that is on an upper surface of the second dielectric substrate, the second upper metal layer including a second upper signal trace;
• a metal signal trace connector that electrically connects the first upper signal trace to the second upper signal trace;
• and
• an RF shielding cover that covers the metal signal trace connector.