Marchand balun structure and design method

摘要

Aspects of the invention provide for a Marchand balun structure and a related design method. In one embodiment, a marchand balun structure includes: a first trace for an unbalanced port on a first metal layer, the first trace comprising: an unbalanced line including a first width for a first half and a second width for a second half, wherein the second width can be different from the first width; a pair of traces for balanced ports on a second metal layer, the pair of traces comprising: a pair of balanced lines; and a ground plane on a third metal layer, the ground plane comprising: a pair of openings directly under the pair of traces for balanced ports, wherein a center of the unbalanced line of the first trace is offset from a center of the pair of balanced lines of the pair of traces.