Self-Biased Nonreciprocal Microstrip Phase Shifter on Magnetic Nanowired Substrate Suitable for Gyrator Applications

• Published in: IEEE transactions on microwave theory and techniques 2012-07, Vol.60 (7), p.2152-2157
• Main Authors: Hamoir, G., De La Torre Medina, J., Piraux, L., Huynen, I.
• Format: Article
• Language: English
• Subjects: Alumina; Applied sciences; Circuit properties; Circuits of signal characteristics conditioning (including delay circuits); Devices; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Exact sciences and technology; ferromagnetic nanowires; gyrator; Gyrators; integrated; Magnetic resonance; Mathematical models; Microstrip; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwave devices; Microwaves; Nanocomposites; Nanomaterials; Nanostructure; Nanowires; nonreciprocal; Permeability; phase shifter; Saturation magnetization; self-biased; Substrates
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2012.2195016

Magnetic nanowired substrates (MNWS) have been used for the fabrication of a planar nonreciprocal microstrip device. It shows a differential phase shift of 300 degrees cm -1 at K a -band without requiring the application of a dc bias magnetic field, and making it suitable for miniaturized gyrator applications. The nonreciprocal operation is achieved by loading the device with nanowires of different ferromagnetic materials. This allows to control the phase velocity of the microwave signal passing through the device by virtue of the spatial variation of the MNWS permeability. The measured microwave performances of the device have been reproduced with excellent accuracy using a proposed analytical model based on an effective medium theory and useful for the prediction of further tunable capabilities.