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MA: Magnetismus
MA 20: Poster: Films(1-36) Transp(37-56) Ex.Bias(57-67) Spindyn(68-80) Micromag(81-95) Particle(96-109) Imag.+Surface(110-113) Spinelectr(114-122) Theory+Micromag(123-131) Spinstr+Aniso(132-142) MagMat(143-156) Meas(157,158) MolMag+Kondo(159-162) Postdead(163-)
MA 20.70: Poster
Tuesday, March 28, 2006, 15:15–19:15, P1
Internally tunable notch filters and attenuators for microwave devices using ferromagnetic resonance absorption — •Tobias Korn1, Ursula Ebels2, Philippe Ferrari3, and Pascal Xavier3 — 1Institut für Angewandte und Experimentelle Physik, Universität Regensburg, 93040 Regensburg — 2SPINTEC CEA/CNRS, 17 Rue des Martyrs, 38054 Grenoble, France — 3IMEP, 23 Rue des Martyrs,38054 Grenoble, France
We present a new concept for internally tunable microwave attenuators and notch filters using microstructured ferromagnets as absorptive elements. The devices consist of a Permalloy (Py, Fe20Ni80)line which is inductively coupled to a coplanar waveguide structure. At its ferromagnetic resonance frequency, the Py line absorbs microwave power from the waveguide. The resonance frequency at zero external bias field may be tailored to device applications by using shape anisotropy. If a DC current is passed through the waveguide, it creates a local in-plane hard-axis magnetic field. This field changes the equilibrium angle of the magnetization of the Py line and thus reduces its resonance frequency. In fixed-frequency attenuation applications at a certain operating frequency f0, the attenuation in the Py line may thus be tuned using a DC current to move its resonance frequency closer to or farther away from f0. For higher applied DC currents, the ferromagnetic absorption may be suppressed completely. No externally created magnetic fields are necessary in these applications, enabling the attenuator and notch filter to be used in miniaturized or mobile devices.