22 research outputs found
Analysis of Electromagnetic Scattering from Array of Time-Modulated Graphene Ribbons
An accurate and fast method is presented for scattering of electromagnetic
waves from an array of time-modulated graphene ribbons. We derive a time-domain
integral equation for induced surface currents under subwavelength
approximation. Using the method of harmonic balance, this equation is solved
for a sinusoidal modulation. The solution of the integral equation is then used
to obtain the transmission and reflection coefficients of time-modulated
graphene ribbon array. The accuracy of the method was verified through
comparison with results of full-wave simulations. In contrast with previously
reported analysis techniques, our method is extremely fast and can analyze
structures with a much higher modulation frequency. The proposed method also
provides interesting physical insights useful for designing novel applications
and opens up new vistas in the fast design of time-modulated graphene-based
devices
Calculation of effective parameters of high permittivity integrated artificial dielectrics
Local Excitation of a Perfectly Conducting Slab With Finite or Infinite Number of Slits and the Role of Proper Complex Waves
High-quality integrated inductors based on multilayered meta-conductors
We demonstrate high-quality integrated inductors built from a multilayer of alternating copper and ferromagnetic films. The multilayer acts as a meta-conductor whose effective permeability becomes nearly zero at its ferromagnetic anti-resonance frequency. This leads to a suppression of the skin effect and a significant increase in the quality factor of the device. Experiments show an up to 86% increase in quality factor compared to conventional copper-based spiral inductors at high frequencies. Ā© 2012 IEEE
High-quality integrated inductors based on multilayered meta-conductors
We demonstrate high-quality integrated inductors built from a multilayer of alternating copper and ferromagnetic films. The multilayer acts as a meta-conductor whose effective permeability becomes nearly zero at its ferromagnetic anti-resonance frequency. This leads to a suppression of the skin effect and a significant increase in the quality factor of the device. Experiments show an up to 86% increase in quality factor compared to conventional copper-based spiral inductors at high frequencies. Ā© 2012 IEEE
Nonreciprocal spin wave spectroscopy of thin NiāFe stripes
The authors report on the observation of nonreciprocal spin wave propagation in a thin ( ? 200?nm) patterned NiāFe stripe. The spin wave transmission spectrum is measured using a pair of microstrip lines as antennas. The nonreciprocity of surface wave dispersion brought about by an adjacent aluminum ground leads to a nonreciprocal coupling of the antennas. The effects of NiāFe film conductivity, thickness, and reflections caused by the lateral confinement of the magnetic stripe are discussed. The nonreciprocity observed in this structure can potentially be used to realize nonreciprocal microwave devices on silicon.Microelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc