A novel approach for logic state dependent generation of polarized photon is proposed, where the logic states '0' and '1' are represented by two sub-spaces in the Hilbert space of the hyperfine states of rubidium atom (87Rb). Each subspace consists of a ground state, an intermediate state and an excited state. The atom is placed at the center of a two-mode cavity, and the cavity modes correspond to frequencies of the generated photon. Photon generation process involves raising the atom to the excited state within the corresponding subspace and letting it decay back to the initial (ground) state, emitting thereby a photon of logic state dependent polarization. In order to keep the driving laser frequencies far off from the cavity mode frequencies, the atom is raised to the excited state in two steps --- first from the ground state to the intermediate state and then from the intermediate state to the excited state. Polarization states of the photon represent the logic states, and can be used to transport logic from one node to another of the quantum network.
The design, simulation and fabrication of a left-handed metamaterial (LHM) structure is presented. The combination of the modified square rectangular Split Ring Resonator (SRR) and the Capacitance Loaded Strip (CLS) were used to obtain the negative value of permeability, μ and the negative permittivity, ε. Nicolson-Ross-Wier approach was used to identify the double negative region. A good agreement between simulated and measured results has been achieved. Upon incorporation with a single patch microstrip antenna, the performance of the antenna was improved where the gain of the microstrip antenna was increased up to 4 dB, and its bandwidth widens from 2.9% to 4.98%. These improvements are due to the negative refraction characteristics of the LHM structure that acts as a lens when placed in front of the antenna.
We show theoretically that the absorption of one dimensional metal-organic periodic structure (1D MOPS) can be enhanced due to organic constituents. We have used simple transfer matrix method to calculate the absorption, transmittance and reflectance of the 1D MOPS systems. The absorption, transmittance and reflectance of 1D MOPS containing periodic of Ag/N,N'-bis-(1-naphthyl)-N,N'diphenyl-1,1'biphenyl-4,4'diamine (NPB) structure are calculated taking optical constant of NPB [1] and Ag [2]. The enhanced absorption of the considered structure is obtained in the visible and in the near infrared regions. Besides this we have also studied the absorption, transmittance and reflectance of the 1D MOPS with air and glass substrates. We find that the absorption is enhanced with variation of thickness of organic layer (NPB). Such absorption enhancement in 1D MOPS could allow many potential applications in photo-thermal technology, thermo photo-voltaic and blackbody emission.
A closed form solution is here proposed for evaluating the field diffracted by the edge of a lossless, isotropic and homogeneous double-negative metamaterial slab when illuminated by a plane wave at skew incidence. It is obtained by considering a Physical Optics approximation of the electric and magnetic equivalent surface currents in the radiation integral and by performing a uniform asymptotic evaluation of this last. The final expression is given in terms of the Geometrical Optics response of the structure and the standard transition function of the Uniform Geometrical Theory of Diffraction, so that it results easy to handle and simple to implement in a computer code. As demonstrated by numerical tests, it allows one to compensate the discontinuities of the Geometrical Optics field at the reflection and incidence shadow boundaries. Moreover, the accuracy of the solution is well assessed by means of comparisons with a commercial tool based on Finite Element Method.
In this work, the dyadic Green functions for different parts of a coaxial tubular filter are derived. Using the obtained data, it is possible to consider the circuit model of a coaxial tubular filter. Moreover, the reactance due to the discontinuity of the matching section (dielectric loaded part) is calculated.
In this paper, jerk function for a transient process of RL circuit is investigated. Some new concepts such as time rate of change of induced emf, time rate of change of displacement current, and Appell function have been introduced for the first time in electromagnetic jerky dynamics. The problems on Appell function of several simple models in electromagnetic jerky dynamics are discussed. In the last conclusions and remarks are also presented.
In this paper, a novel view of a switched reluctance motor under dynamic eccentricity fault to provide the precise and reliable electromagnetics model is presented. It describes the performance characteristics and comparison results of the 6/4 switched reluctance motor with dynamic rotor eccentricity utilizing three-dimensional finite element analysis. The results obtained using three-dimensional finite element analysis of the switched reluctance motor includes flux-linkages, terminal inductance per phase, mutual inductances and static torque for various eccentric motor conditions. In this analysis the end effects and axial fringing fields for simulating reliable model are obtained and presented. The paper continues with comparing these results with the ones obtained for the same motor profile but utilizing two-dimensional finite element method. Finally, Fourier analysis is carried out to study the variations of torque harmonics.
A uniform geometrical theory of diffraction (UTD) enhanced physical optics and time domain integral equation (PO-TDIE) hybrid algorithm is proposed. UTD is applied to calculate the edge effect and to compensate the calculation error made by the PO current approximation. This method can improve the accuracy while maintaining the computational complexity, compared to PO-TDIE. Numerical result illustrates the validity and efficiency of the proposed method.
Focal region fields of perfect electromagnetic conductor (PEMC) paraboloidal reflector placed in homogenous and reciprocal chiral medium are analyzed. Maslov's method is used to derive the expressions for the focal region fields because the geometrical optics (GO) fails at these points. The results obtained by this method are solved numerically, and line plots for the reflected field of the paraboloidal PEMC reflector are obtained for di®erent values of admittance of the PEMC reflector and chirality parameter of the medium.
This paper deals with an inverse source problem starting from the knowledge of the radiated field in Fresnel and near zone. In particular, here we are concerned with a 2D geometry characterized by a rectilinear magnetic source and measurement rectilinear domains in Fresnel and near zone. The effect of the added knowledge of the radiated field over a second observation domain is investigated via the Singular Values Decomposition of the radiation operator and we point out how the addition of a second observation domain allows us always to achieve a better noise rejection. Also, we determine conditions under which the knowledge of the field over the second domain increases the information content (as the number of singular values of the radiation operator before their asymptotic decay) for both the Fresnel and near zone cases. Finally reconstruction examples with noise-free and noisy data are presented.
A Computer Aided Design (CAD) approach based on Artificial Neural Networks (ANN's) is successfully introduced to determine the characteristic parameters of Circular-shaped Microshield and Conductor-Backed Coplanar Waveguide (CMCB-CPW). ANN's have been promising tools for many applications and recently ANN has been introduced to microwave modeling, simulation and optimization. The Multi Layered Perceptron (MLP) neural network used in this work were trained with Levenberg-Marquart (LM), Bayesian regularization (BR), Quasi-Newton (QN), Scaled Conjugate gradient (SCG), Conjugate gradient of Fletcher-Powell (CGF) and Conjugate Gradient backpropagation with Polak-Ribiere (CGP) learning algorithms. This has facilitated the usage of ANN models. The notable benefits are simplicity & accurate determination of the characteristic parameters of CMCBCPW's. The greatest advantage is lengthy formulas can be dispensed with.
Practical antenna array designs generally require that the elements are separated by electrically short distances. The resultant mutual coupling often adversely affects the achievable performance. Various methods are available to quantify the effects of mutual coupling in arrays and improve performance through mutual coupling compensation. Mutual coupling is often described by a coupling matrix that relates the coupled and uncoupled quantities. Unfortunately, the accuracy with which the coupling matrix can be calculated is highly dependent on both the method selected and the frequency. This is a significant limitation for wideband analysis where the coupling matrix needs to be calculated accurately at all frequencies of interest. This paper introduces a novel method for the precise calculation of the coupling matrix at any frequency of interest. It is an extension of the induced EMF method to multiple array elements. The method has the important practical advantage of being independent of the numerical technique used in the analysis. Since the coupling matrix is calculated by exciting the elements in the transmission mode, the method resembles well-known network analysis. However, as outlined in the paper, there are subtle differences between the two approaches, which lead to more accurate results with the new proposed method. It is also demonstrated that antennas with arbitrary geometries and illuminations are handled accurately by the method.
High-order modes of spoof surface plasmon polaritons (SPPs) on the periodically corrugated metal surfaces are investigated theoretically with the modal expansion method. An analytical expression for the condition of existence of high-order modes is presented. The properties of high-order modes such as dispersion and field pattern are analyzed detailedly, from which it seems that the propagation of spoof SPPs along the corrugated metal surface is mainly based on the coupling between the open groove cavities.
Abstract：A hybrid high-frequency solution is proposed to analyze the bistatic electromagnetic scattering of the ship target on very large two-dimensional randomly rough sea surface in this paper. The comprehensive geometrical model of the ship and sea surface is designed by CAD tools and the sea power spectrum, and its electromagnetic scattering characteristic is evaluated with the method of equivalent currents (MEC). Since the electromagnetic interaction between the ship hull and the sea surface in the vicinity of the broadside is similar to the scattering mechanism of the dihedral reflector, the iterative physical optics method (IPO) is utilized to study the electromagnetic coupling effects. The shadowing correction based on the Z-Buffer technology is introduced to eliminate the effects of the irrelevant scattering resources. At last, the validity of the hybrid method is confirmed by the SAR image of the ship on the very large two-dimensional sea surface, and the numerical results are presented to analyze the composite scattering characteristics of the ship on the sea surface.
In the present investigation, diffraction from a slit in perfectly electromagnetic conducting (PEMC) plane has been studied. Both the E- and H-polarization are considered and the method of analysis is Kobayashi Potential (KP). The mathematical formulation involves dual integral equations (DIEs). These DIEs are solved by using the discontinuous properties of Weber-Schafheitlin's integral. The resulting expressions, finally, reduce to matrix equations. These are then used to compute the values of unknown expansion coefficients. Numerical results are presented for different parameters of interest especially the dependance of co-polarized and cross-polarized components on the admittance parameter.
Electromagnetic fields in a cavity filled with double negative dispersive medium and bounded by a closed perfectly conducting surface is studied in the Time Domain. The sought electromagnetic fields are found in a closed form by using decomposition over cavity modes and solving in TD the differential equations for the time varying mode amplitudes. Some features of frequency response of such an electromagnetic system are presented. Waveforms of electromagnetic fields excited by a wideband pulse are considered.
There are three approaches for the solution of the diffraction problem of plane waves by an impedance half-plane in the literature. The diffracted field expressions, obtained by the related methods, are compared numerically. The examination of the scattered field shows that the most reliable solution is the field representation of Raman and Krishnan. Since the diffracted fields of Senior and Maliuzhinets do not compensate the discontinuities of the geometrical optics waves at the transition regions.
We demonstrate complete tunneling of light through large-scale mu-negative media, which has negative permeability but positive permittivity, by constructing a quasi-one-dimensional structure with side branches. For the structure with a single side branch, there always exists a transmission peak which can be easily tuned by varying the parameters of the side branch. For the structure with periodic array of side branches, the transmission peak is enlarged to a band, which exhibits left-handedness, and can be tuned by changing the distance between two neighboring side branches and the length of the side branch.
In this paper we derived the formula for calculating the mutual inductance between circular filaments with lateral and angular misalignment by using the approach of the magnetic vector potential. The results obtained correspond to those of F. W. Grover, although the latter used the general formula given by the Neumann integral instead of a vector potential approach. However, the major purpose of this paper is to clarify some confusion introduced in previous works regarding the mutual inductance calculation between thin filamentary circular coils with parallel axes in air. This problem has been solved by Kim et al. (1997) using the magnetic vector potential, but unfortunately it leads to erroneous results, even for slight misalignments of the coils' center axes. This is why we chose to use the approach of the magnetic vector potential to show that, when properly derived, the results must indeed reduce to the well known F.W. Grover's formulas.
A method based on adaptive-network-based fuzzy inference system (ANFIS) is presented for the analysis of conductor-backed asymmetric coplanar waveguides (CPWs). Four optimization algorithms, hybrid learning, simulated annealing, genetic, and least-squares, are used to determine optimally the design parameters of the ANFIS. The results of ANFIS models are compared with the results of conformal mapping technique, a commercial electromagnetic simulator IE3D, and the experimental works realized in this study. There is very good agreement among the results of ANFIS models, quasi-static method, IE3D, and experimental works. The proposed ANFIS models are not only valid for conductor-backed asymmetric CPWs but also valid for conductor-backed symmetric CPWs.
Submit
