Patent ID: 6573597
Filing Date: 2003-06-03
Classification: H01L,H01P,H05K

Abstract:
Apparatus comprising:a substrate having a flat surface that is substantially planar and free of trenches; a first quasi-coaxial transmission line fabricated upon the substrate; a second quasi-coaxial transmission line fabricated on the same side of the substrate as the first quasi-coaxial transmission line and crossing over the first quasi-coaxial transmission line; and wherein each quasi-coaxial transmission line is fully shielded and each comprises a respective lower ground shield deposited on the flat surface of the substrate, a bottom ribbon of dielectric material deposited on the lower ground shield, a center conductor deposited on the bottom ribbon of dielectric material, a top ribbon of dielectric deposited over the center conductor and the bottom ribbon of dielectric material, and a unitary upper ground shield deposited as a single unit over the combined top and bottom ribbons of dielectric material, the unitary upper ground shield being, at locations along the first quasi-coaxial transmission line and at locations along the second quasi-coaxial transmission line different from where it crosses over the first quasi-coaxial transmission line, in continuous physical contact with opposing locations of the lower ground shield on each side of the bottom ribbon of dielectric material; and further wherein at the location where the second quasi-coaxial transmission line crosses over the first quasi-coaxial transmission line: (a) the bottom ribbon of dielectric material of the second quasi-coaxial transmission line, the center conductor of the second quasi-coaxial transmission line, the top ribbon of dielectric material of the second quasi-coaxial transmission line and the unitary upper ground shield of the second quasi-coaxial transmission line, extend over the first quasi-coaxial transmission line; (b) the unitary upper ground shield of the first quasi-coaxial transmission line serves as a portion of the lower ground shield of the second quasi-coaxial transmission line; and (c) an extended portion of unitary upper ground shield for the second quasi-coaxial transmission line that crosses over the first quasi-coaxial transmission line is in continuous physical contact on opposing its sides with a crossed-over portion of the unitary upper ground shield of the first quasi-coaxial transmission line.