The Horizon Europe project PATTERN will develop the world’s first Process and Assembly Design Kits (PDK & ADK) for microwave photonics at ultra‐high frequencies (100+ GHz) as well as new methods or heterogeneous integration of III-V gain materials (e.g. InP) and BiCMOS drivers with electro-optic and nonlinear platforms such as lithium niobate on insulator (LNOI). It also envisions new and advanced PIC building blocks, such as acousto-optic modulators (AOMs) and magneto-optic insulators.