Frequency dependence of microwave complex permeability under magnetic bias

Frequency-dependence of Relative Permeability in Steel

A study to characterize metal plates by means of a model-based, broadband, four-point potential drop measurement technique has shown that the relative permeability of alloy 1018 low-carbon steel is complex and a function of frequency. A magnetic relaxation is observed at approximately 5 kHz. The relaxation can be described in terms of a parametric (Cole-Cole) model. Factors which influence the ...

Coexistence under positive frequency dependence.

Negative frequency dependence resulting from interspecific interactions is considered a driving force in allowing the coexistence of competitors. While interactions between species and genotypes can also result in positive frequency dependence, positive frequency dependence has usually been credited with hastening the extinction of rare types and is not thought to contribute to coexistence. In ...

Anomalous bias dependence of spin torque in magnetic tunnel junctions.

We predict an anomalous bias dependence of the spin transfer torque parallel to the interface, Tparallel, in magnetic tunnel junctions, which can be selectively tuned by the exchange splitting. It may exhibit a sign reversal without a corresponding sign reversal of the bias or even a quadratic bias dependence. We demonstrate that the underlying mechanism is the interplay of spin currents for th...

Frequency dependence of the magnetic response of split-ring resonators

Bias Reduction for Direct Frequency Estimator of Complex Sinusoid

Frequency estimation of single-tone complex sinusoid is a fundamental problem in signal processing. An efficient way to estimate the frequency is to directly calculate the frequency from three discrete Fourier transform coefficients in the neighborhood of peak magnitude spectrum. Because of the approximation used in the calculation, these direct estimators exhibit non-uniform biases. In this pa...