A surface mountable transformer integratable into a printed circuit board. In one aspect, the transformer (300) comprises two broadside vertically coupled transmission lines (304,308,312,316). In another aspect, the transformer may comprise two broadside vertically partially coupled transmission lines. The layout of the transformer is adaptable for use in microwave modules where transformers are integrated into the printed circuit board and the active components are mounted in the cavity. The layout preferably requires only two signal areas. In addition, an aspect of the present invention allows the differential or unbalanced ports to lie on the same surface as the balanced port.