Methods are provided for building integrated circuit transformer devices having compact universal and scalable architectures for millimeter wave applications. For example, an integrated circuit transformer (22) is formed on a semiconductor substrate (21) and includes a ground shield (23) formed on the substrate (21), a primary conductor (24) comprising an elongated conductive strip and a secondary conductor (25) comprising an elongated conductive strip. The primary conductor (24) and the secondary conductor (25) are aligned to form a coupled-wire structure that is disposed adjacent to the ground shield (23). The ground shield (23) comprises a pattern of close-ended parallel elongated slots (23a) and parallel conductive strips (23b) that are commonly connected at end portions thereof alongedge regions (23c) of the ground shield (23). The slots (23a) and strips (23b) are disposed orthogonal to the primary (24) and secondary (25) conductors. The edge regions (23c) provide current returnpaths that are collinear to the primary (24) and secondary (25) conductors. The integrated circuit transformer (22) can be used as template or building block, which is parameterized by length, for constructing various integrated circuit devices and modular structures including, but not limited to, power amplifiers, n:l impendence transformers, and power combiners.