RF Planar Ferromagnetic Inductors on Silicon

High-frequency behavior of magnetic composites

“…These relations may also be useful in considerations of other technical applications for magnetic composites, such as smallsized wideband antennas [125], microwave inductors [126,127], resonance filters, etc. In all these applications, high microwave permeability is needed, though magnetic loss must be low.…”

Permeability enhancement of soft magnetic films through metamaterial structures

“…This provides unique opportunities with regard to tuning of microwave magnetic properties for various silicon-based applications, such as inductors [14,15], filters [16,24], couplers, etc. However, a more general question is whether metafilms can outdo conventional magnetic films.…”

“…Conventional magnetic materials have been used in conjunction with metamaterial patterns in various ways [9,10], and in particular, magnetic cores made of ferrite or ferromagnetic wires [11,12] have been shown to boost the permeability levels attainable in magnetic metamaterials. However, until recently [13], no metamaterial structure that is capable of replacing or supplementing individual magnetic thin films used for silicon-based applications [14,15] has been proposed.…”

“…In contrast to most planar metamaterial structures, e.g., Split Ring Resonators [1,4], the permeability features are observed for an in-plane microwave magnetic field. This is a very desirable feature, since the microwave magnetic field is generally in-plane for siliconbased applications [14][15][16]. Experimental results are reported, and it is shown that an existing analytical model accounts for the measured permeability of such materials.…”

Sum rules and figures-of-merit on the microwave permeability of nanocrystalline microwires

“…Since the pioneering ferromagnetic resonance (FMR) experiments by Kittel [1], the high-frequency response of magnetic materials is known to be a powerful investigation tool, either under the conventional FMR approach or through microwave permeability measurements. The quantity m(F) is also of interest for a number of technological applications [2] ranging from self-standing voltage converters [3] to integrated inductors [4] and electromagnetic noise suppressors [5]. For most of these applications, high-permeability levels are desired up to increasingly higher frequencies.…”