A structure, comprising: a pair of structure members (12, 24) separated by a gap, each one of the pair of structure members having a microwave transmission line (30, 15); an interconnect structure disposed in the gap, the interconnect structure comprising: a fill-structure having opposing sides in direct contact with the opposing sides of a first one of the pair of structure members and a second one of the pair of structure members; an interconnecting microwave transmission line disposed on the fill-structure electrically interconnecting the microwave transmission line of the first one of the pair of structure members to the microwave transmission line of the second one of the pair of structure members; an electrically conductive member disposed over a signal line of the interconnecting microwave transmission line; and an electrically conductive layer between the fill-structure and the interconnecting microwave transmission line; a dielectric layer disposed between the electrically conductive layer and the interconnecting microwave transmission line; wherein the interconnecting microwave transmission line includes a signal conductor and a ground conductor; wherein the electrically conductive member is disposed over the signal conductor; and wherein the electrically conductive member is electrically connected to the ground conductor, and the electrically conductive layer is electrically connected to the electrically conductive member and to the ground conductor. a pair of structure members (12, 24) separated by a gap, each one of the pair of structure members having a microwave transmission line (30, 15); an interconnect structure disposed in the gap, the interconnect structure comprising: a fill-structure having opposing sides in direct contact with the opposing sides of a first one of the pair of structure members and a second one of the pair of structure members; an interconnecting microwave transmission line disposed on the fill-structure electrically interconnecting the microwave transmission line of the first one of the pair of structure members to the microwave transmission line of the second one of the pair of structure members; an electrically conductive member disposed over a signal line of the interconnecting microwave transmission line; and an electrically conductive layer between the fill-structure and the interconnecting microwave transmission line; a dielectric layer disposed between the electrically conductive layer and the interconnecting microwave transmission line; a fill-structure having opposing sides in direct contact with the opposing sides of a first one of the pair of structure members and a second one of the pair of structure members; an interconnecting microwave transmission line disposed on the fill-structure electrically interconnecting the microwave transmission line of the first one of the pair of structure members to the microwave transmission line of the second one of the pair of structure members; an electrically conductive member disposed over a signal line of the interconnecting microwave transmission line; and an electrically conductive layer between the fill-structure and the interconnecting microwave transmission line; a dielectric layer disposed between the electrically conductive layer and the interconnecting microwave transmission line; wherein the interconnecting microwave transmission line includes a signal conductor and a ground conductor; wherein the electrically conductive member is disposed over the signal conductor; and wherein the electrically conductive member is electrically connected to the ground conductor, and the electrically conductive layer is electrically connected to the electrically conductive member and to the ground conductor.