Magnetic Nanoferrites for RF CMOS: Enabling 5G and Beyond

The upcoming 5th generation (5G) telecommunication technology will enable realization of the full potential of the Internet-of-things (IoT) by utilizing various frequency bands, ranging from <4 GHz to 100 GHz. A brief review of the technical requirements of RF CMOS at the unveiling of the 5G system is provided. Key challenges associated with 5G are illustrated, with a focus on the need for, and state of the art of, magnetic materials, especially ferrites, in enhancing the performance of RF integrated circuits. The suitability of a low-temperature, CMOS-compatible, on-chip ferrite thin film deposition technique, which was elusive until recently, is compared with traditional deposition processes for thin ferrite films. The uniqueness of this microwave-irradiation-assisted, far-from-equilibrium, solution-based deposition technique in achieving an unusually high ferromagnetic resonance frequency is discussed. The effect of magnetic ferrite films in niche applications such as in X-band (8~12 GHz) inductors and K-band (18~40 GHz) electromagnetic noise suppressors is discussed and demonstrated.