Homayoon Oraizi

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—It is proposed that the application of defected ground structures (DGS) and electromagnetic bandgap (EBG) reduce the phase velocity, increase effective permittivity of microstrips and reduce the effective the wavelength which eventually lead to the reduction of overall length of Wilkinson power dividers. Furthermore, the adjacent strip lines may approach(More)
—In this paper the electromagnetic wave scattering from multilayered cylindrical structures is studied for a normally incident plane wave with linear (TE or TM), circular and elliptical polarizations. The cylindrical layers may be composed of any combination of dispersive common materials and metamaterials. The addition theorems for the cylindrical waves(More)
—We introduce and investigate the applications of double zero (DZR) metamaterials (having the real parts of permittivity and permeability equal to zero) as radar absorbing materials (RAMs). We consider a perfectly electric conductor (PEC) plate covered by several layers of DZR metamaterial coatings under an oblique plane wave incidence of arbitrary(More)
—In this paper, the vector parabolic equation method (VPEM) is used to investigate the Shannon capacity of multiple-input multiple-output (MIMO) communication systems in indoor corridors. This deterministic three-dimensional (3-D) full-wave method is capable to demonstrate the effects of antennas and propagation environment on the channel capacity. The VPEM(More)
—The influence of semi-planar chiral metamaterial (CMM) structures on the important characteristics of circularly polarized (CP) antennas is investigated in this paper. Based on this idea, CP planar two-arm Archimedean spiral (ARSPL) antenna and helical antenna are designed and the effects of chiral covers on their gain (or directivity), axial-ratio (AR),(More)
—A dielectric resonator loaded patch antenna excited by a coaxial cable is proposed in this paper. The results from measurement show a wide impedance bandwidth of 57.1% from 3.75 GHz to 6.75 GHz and a peak gain of 11.5 dB at the center of frequency band with an average gain improvement of 3 dB over the frequency band in comparison with the common dielectric(More)
—The transmission line transfer matrix method (TLTMM) is proposed for the analysis of planar multilayer metamaterial (MTM) structures, where a transmission line model is developed by the transfer matrix method. This novel method may consider any oblique incident plane wave at any angle of incidence, any linear polarization (TE or TM with respect to the(More)