Integrated and self-biased planar magnetic microwave circuits based on ferromagnetic nanowire substrates

We present a process for the fabrication of ferromagnetic nanowire (FMNW) substrates for integrated magnetics by selective deposition into nanoporous alumina membranes. In addition to integration, these substrates offer the strong benefit of self-biasing, removing the need for an external magnet. Devices prepared by this process are compatible with PCB and MMIC technologies, permitting the production of integrated magnetic circuits. The effective permittivity and permeability of the FMNW substrates have been extracted for microstrip technology. Full-wave simulations demonstrate the possibility of an unbiased, integrated, microstrip circulator and edge-mode isolator.