US Patent 7119633 Compensated interdigitated coupler

A coupler may include four ports, and first and second sets of conductive strips. Each set of conductive strips may include a plurality of interconnected conductive strips connected between two ports. Each conductive strip of the first set may be electromagnetically coupled to a conductive strip of the second set. Conductive tabs capacitively coupled directly or indirectly to the ground conductor may extend from conductive strips of the first and second sets. An interconnection may be positioned between adjacent tabs, the interconnection connecting conductive strips of one of the sets of conductive strips. The adjacent tabs may be spaced different distances from the interconnection.