US Patent 7821372 On-chip transformer BALUN structures

An electronic device includes a first winding having a first port and a second port. The first winding formed in a first metal layer. A second winding has a third port and a fourth port. The second winding includes a plurality of segments formed in the first metal layer. The second plurality of winding segments are connected by a bridge formed in a second metal layer. The first and second ports of the first winding are connected to the inner-portion of the first winding.