Patent ID: 8179137

Claim:
A balun capable of operating in a magnetic resonance imaging system, the balun configured to block induced radio frequency current on ground conductors of a stripline multi-layer signal carrier without requiring conversion into or out of a coaxial cable, the multi-layer signal carrier including alternating signal conductors and the ground conductors, the balun comprising: first and second insulative elements disposed on first and second sides of the multi-layer signal carrier, respectively; a conductive layer partially coating an exterior of each insulative element, wherein the conductive layer does not coat a central region of each insulative element substantially transverse to a direction of the multi-layer signal carrier, such that each insulative element comprises a first conductively coated region and a second conductively coated region separated from one another by the central region that is not conductively coated, wherein the central region is substantially equidistant to an entrance of the multi-layer signal carrier into the balun and an exit of the multi-layer signal carrier out of the balun; first and second capacitive circuits respectively coupling the first and second conductively coated regions of each respective insulative element across the central regions thereof; vias extending through the multi-layer signal carrier; and conductive material disposed in the vias electrically coupling the first conductively coated regions of the insulative elements with the ground conductors around the entrance of the multi-layer signal carrier into the balun and the second conductively coated regions of the insulative elements with the ground conductors around the exit of the multi-layer signal carrier out of the balun.