Correlation between magnetic properties of layered ferromagnetic/dielectric material and tunable microwave device applications

Abstract

Analysis of the mode composition of an X-band overmoded O-type Cerenkov high-power microwave oscillator Phys. Plasmas 19, 103102 (2012) Gap independent coupling into parallel plate terahertz waveguides using cylindrical horn antennas J. Appl. Phys. 112, 073102 (2012) A band-pass filter approach within molecular dynamics for the prediction of intrinsic quality factors of nanoresonators J. Appl. Phys. 112, 074301 (2012) A research of W-band folded waveguide traveling wave tube with elliptical sheet electron beam Phys. Plasmas 19, 093117 (2012) Dual-band terahertz metamaterials based on nested split ring resonators Layered dielectric / ferromagnetic materials are extensively explored for microwave applications. Indeed, these materials combine the large saturation magnetization of ferromagnetic material with the low loss of dielectrics. Here, our aim was to integrate a layered ferromagnetic composite in a microwave propagation structure since the main advantage of such a material is the large impedance for one polarization. Thus, in order to predict the transmission response of the device, we carried out an electromagnetic analysis to determine how the field pattern of a microstrip line and the microwave-induced demagnetizing fields disturb the material behavior. We also explored the use of the propagation structure in two dc magnetic field-dependent devices: a tunable band stop filter and a magnetic switch. The stop-band function presented a large tunability of more than 50% with a minimal insertion loss of 3 dB when 250 Oe field was applied. Moreover, a magnetic switch using a dc field perpendicular to the easy axis of the ferromagnetic material was manufactured.

10 GHz bandstop microstrip filter using excitation of magnetostatic surface wave in a patterned Ni78Fe22 ferromagnetic film

“…The low-frequency peak of attenuation constant versus frequency can be associated with FMR of a ferromagnetic core. [1][2][3][4][5][6][7][8] The observed frequency shift with respect to the expected thin-film FMR frequency ͑2.4 GHz͒ is partly due to the combination of a high magnetic damping constant and a small width of a signal line, 9 as well as the influence of a high-frequency component ͑peak HF͒. For sample B, the attenuation constant versus frequency demonstrates no low-frequency FMR component but only a high-frequency contribution close to 10 GHz ͓Fig.…”

“…[1][2][3][4][5][6] In particular, it was demonstrated for a microstrip with yttrium iron garnet magnetic core, saturated perpendicular to the plane of the strip line, that transmission characteristics of the line show strong coupling phenomena between quasi-TEM and magnetostatic surface wave ͑MSSW͒ modes. 2 On the other hand, for a microstrip with a tangentially ͑in-plane͒ magnetized magnetic core, the effect of the MSSW mode has been ignored; even the possible tracks of these modes can be seen from experimental data.…”

The effect of a neighboring metal layer on the high-frequency characteristics of a thin magnetic stripe

“…[1][2][3][4][5][6][7] Such studies are particularly important in view of the potential application of FM elements in magnetic data storage and microwave devices. [8][9][10][11] In many cases, however, magnetic elements do not stand alone, but are ͑par-tially͒ surrounded by metallic conductors. One, for instance, can think of microwave transmission lines with FM cores [9][10][11] or inductive techniques utilizing coplanar waveguides for probing magnetization dynamics in thin films.…”

“…[8][9][10][11] In many cases, however, magnetic elements do not stand alone, but are ͑par-tially͒ surrounded by metallic conductors. One, for instance, can think of microwave transmission lines with FM cores [9][10][11] or inductive techniques utilizing coplanar waveguides for probing magnetization dynamics in thin films. 12,13 Nevertheless, the effect of neighboring metallic layers on the spinwave spectra of confined magnetic samples has not been investigated, although the former's influence on the dispersion relation of spin waves in infinite films is well known.…”

Microwave absorption of patterned arrays of nanosized magnetic stripes with different aspect ratios

“…Different applications of ferromagnetic metals in tunable microwave filters have recently been developed. [4][5][6][7] The aim of this work is to investigate the effect of shape anisotropy on microwave absorption, which can be used to tailor microwave spectra by designing arrays consisting of stripes or wires with different aspect ratios.…”