Microwave circulator based on ferromagnetic nanowires in an alumina template

Abstract

Unbiased planar microwave circulators were fabricated by electrodeposition of NiFe nanowires into porous alumina templates. Microwave properties of the devices are seen to depend drastically on the height of the nanowires and the newly developed devices exhibit improved features, compared to existing nanowire-based designs. Thanks to the high anisotropy of the nanowires, zerofield circulation modes may be observed in a frequency range from 10 to 30 GHz, with isolation as large as 30 dB, as well as low insertion losses -5 dB, making it compatible with industrial needs for device applications. Abstract Unbiased planar microwave circulators were fabricated by electrodeposition of NiFe nanowires into porous alumina templates. Microwave properties of the devices are seen to depend drastically on the height of the nanowires and the newly developed devices exhibit improved features, compared to existing nanowire-based designs. Thanks to the high anisotropy of the nanowires, zero-field circulation modes may be observed in a frequency range from 10 to 30 GHz, with isolation as large as 30 dB, as well as low insertion losses −5 dB, making it compatible with industrial needs for device applications.

Static and dynamic magnetic properties of densely packed magnetic nanowire arrays

“…The use of MNWA in microwave circulators that do not require an external bias field has already been demonstrated. 9 Ferromagnetic nanowires released from the nanoporous template are also good candidates for the application of force or heat to cells and biomolecules and for the delivery of drugs within biomedical science. 10,11 For effective exploitation of MNWAs it is essential to establish a full understanding of their static and dynamic magnetic properties.…”

Dual behaviors of magnetic CoxFe1−x (0≤x≤1) nanowires embedded in nanoporous with different diameters

“…Ferromagnetic nanowire arrays have been widely investigated to understand their microstructures, magnetic properties and their applications in microwave circulator [1] recording media [2], magnetic nanodevices [3] and nanosensors [4]. To produce nanowire arrays, advanced lithographic techniques [5], electroless procedures [6] and electrodeposition techniques in nanoporous templates have been developed [7][8][9].…”

Self-oriented CoFe2O4composites for non-reciprocal microwave components

“…As was said before, to simulate the device using HFSS, the CoFe 2 O 4 particles and the silica nanowires in the porous membrane are considered as a saturated effective medium with an effective permittivity [1]:…”

“…Microwave circulators have had a serious evolution in the last few decades, whether in performance or in miniaturization, yet the latter is limited due to the need of bulky magnets to orient the ferrite crystal and assure the function of circulation [1]. There are many studies in the world that deal with this issue and many approaches to these studies such as circulators using hexaferrite [2] or ferromagnetic nanowires [3][4][5][6].…”