Folded U-shaped microwire technology for ultra-compact 3D MMICs

A novel microwire technology has been developed to fabricate 3-dimensional structures for use in ultracompact GaAs MMICs. By folding metal into a U-shaped wall and burying it in a relatively thick polyimide insulator, vertical microwires can be made with both greatly reduced process complexity and process compatibility with multi-level interconnects. The proposed microwires are suitable for miniature transmission lines, miniature inductors, shielding walls, and multi-function passive elements like baluns and couplers.