In this paper, a novel power divider integrated with substrate integrated waveguide (SIW) and defected ground structures (DGS) techniques is proposed to provide both power dividing and filtering functions. The SIW technique holds advantages of low profile, low-lost, mass-production, easy fabrication and fully integration with planar circuits. By integrating with defected ground structures (DGS) technique, the size and cost of system can be effectively reduced as the proposed power divider has a function of filtering which leads to reduction of one filter. In order to verify the design approach, the proposed power divider with equal power divisions at the center frequency of 8.625 GHz is fabricated and measured. The measured results demonstrate that the insertion loss is less than 1.2 dB and the input return loss less than 16 dB across the bandwidth of 1.4 GHz (FBW is 16%). Moreover, the imbalances of the amplitude and phase are less than 0.3 dB and 0.5 degree, respectively.

It has been known through some examples that parameters of an electromagnetic medium can be so dened that there is no dispersion equation (Fresnel equation) to restrict the choice of the wave vector of a plane wave in such a medium, i.e., that the dispersion equation is satised identically for any wave vector. In the present paper, a more systematic study to define classes of media with no dispersion equation is attempted. In addition to the previously known examples, a novel class of Case 1 media with no dispersion equation is seen to emerge through the analysis making use of coordinate-free four-dimensional formalism in terms of multivectors, multiforms and dyadics.

D′B′, DB′ and D′B boundary conditions are used to investigate the resulting field patterns inside a parallel plate waveguide. The D′B′ boundary conditions are accomodated by assigning the behavior of perfect magnetic conductor (PMC) for transverse electric mode (TE) and that of perfect electric conductor (PEC) for transverse magnetic (TM) mode, to the boundary, respectively. Likewise, DB′ boundary conditions are incorporated by assuming the behavior of boundary as PMC for both the TE mode and TM mode. Finally D′B boundary conditions are realized by assigning PEC characteristic to the boundary for both TE and TM modes. A general wave propagating inside the parallel plate waveguide is assumed and decomposed into TE and TM modes for the purpose of analysis. Fractional curl operator has been used to study the fractional parallel plate D′B′, DB′ and D′B waveguides for different values of fractional parameter α. Behavior of the field patterns in the waveguides are studied with respect to the fractional parameter α describing the order of the fractionalization.

This paper presents two novel designs of truncated rhombus-like slotted antenna (TRLSA) based on aperture-coupled feeding technique. In conventional antennas, different patch dimensions are required to accommodate different frequencies which normally result in bigger antenna structures. Therefore, this paper proposes a unique structure of `zig-zag' slot embedded on two different antennas to achieve two different resonant frequencies but of the same patch dimensions. An analysis on design transformation which includes comparative simulation results of two reference antennas and TRLSAs has also been presented to provide better understanding on the design concept. CST Microwave Studio software has been used for design simulations and optimizations. The simulation and measurement results of TRLSAs are also presented. The results confirm that the antennas can operate at two different frequencies, 5.3 GHz and 5.8 GHz with the same patch dimensions by integrating the "zig-zag" slot at two different orientations in x- and y-axis respectively. Hence, size reduction is achieved for lower frequency patch which gives a great advantage for future development of a frequency reconfigurable antenna in an array configuration.

In this paper, a miniaturized wideband bandpass filter utilizing a square ring resonator and loaded open-stubs is proposed. One pair of bent open-stubs characterized as perturbations is installed outside the diagonal corners of the ring, and another pair of loaded open-stubs is added inside the ring resonator. By stretching the perturbation stubs more than half-wavelength of the ring, three pairs of degenerated modes in a ring are split for wideband operation. The first two split modes form the dominant passband. Meanwhile, the loading effect introduced by the loaded open-stubs could move the third split mode into the dominant passband, at the same time, an additional transmission zero is generated by the loaded open-stub, which improves the skirt selectivity. Due to the applying of the perturbation stubs as long as more than half-wavelength, this kind of wideband microstrip ring resonator filter occupies a smaller size than those conventional ones that based on ring resonator. To verify the mechanism above, a wideband bandpass filter centered at 3.5 GHz is designed, implemented, and fabricated. Measured results of experimental circuit show good agreement with simulated responses.

We systematically study the Cherenkov optical emission by a nonrelativistic modulated source crossing 3D dispersive metamaterial. It is found that the interference of the field produced by the modulated source with the periodic plasmonic-polariton excitations in a metamaterial leads to the specific interaction in the frequency range where the dispersive refractive index of a metamaterial is negative and the reversed Cherenkov emission is generated. Such resonance considerably modifies the spatial structure of the Cherenkov field. In our study parameters of a metamaterial and modulated source are fixed while the frequency spectrum of the plasmonic excitations is formed due to the fields interplay in the frequency domain.

A novel inductively loaded monopole for current and future ultra-wide-band (UWB) applications is presented. The antenna is compact and of small size (16 mm×20 mm×0.8 mm), and offer a very simple geometry suitable for low cost fabrication and straightforward printed circuit board integration. More specifically, the impedance matching of the classic printed loop loaded monopole is improved by employment of the tapered microstrip feed line between K-connector and the printed monopole. By using this technique, impedance bandwidth (S₁₁ < -10 dB) from 3.03 GHz to over 40 GHz is obtained. Measured and simulated return losses curves are provided along with radiation patterns and gain, as a function of frequency. Compared to the recently reported UWB antennas, the presented antenna have smallest size, widest bandwidth, and simple configuration to realize the application in current and future UWB communication systems. Furthermore, a symmetric radiation patterns and satisfactory gain make the presented antenna a suitable candidate for practical UWB applications.

We study the current distribution and input impedance of a circular loop antenna in the form of an infinitesimally thin, perfectly conducting narrow strip coiled into a ring. The antenna is located on the surface of an axially magnetized plasma column surrounded by a homogeneous isotropic medium. The current in the antenna is excited by a time-harmonic voltage creating an electric field with the azimuthal component in a gap of small angular opening on the strip surface. The emphasis is placed on the solution of the integral equations for the azimuthal harmonics of the antenna current in the case where the magnetoplasma inside the column is nonresonant. The properties of the kernels of the integral equations are discussed and the current distribution in the antenna is obtained. It is shown that the presence of a magnetized plasma column can significantly influence the electrodynamic characteristics of the antenna compared with the case where it is located in the surrounding medium or a homogeneous plasma medium the parameters of which coincide with those inside the column.

Eggs are one of the most nutritious foods available in nature. This rich nutritive environment attracts microbes to invade, feed and multiply. Salmonella enteritidis is one such microbe that is highly pathogenic and is the causative agent for the disease salmonellosis. To ensure safety of eggs, processing them without affecting their unique physical properties is essential. In this study, the impact of radiofrequency (RF) heating on the dielectric properties (dielectric constant and dielectric loss factor) of the egg at varying temperatures (5°C-56°C) and frequency (10 MHz-3 GHz) is evaluated. This study on the dielectric parameters is essential to devise a better heating paradigm wherein there is minimal detrimental effect to the egg components. Based on the dielectric study, the heating process parameters were determined. The effect of such heat treatment on the physical properties viz. Viscosity, foam density, foam stability and turbidity of the egg white were also studied. This study was conducted to provide sufficient literature and experimental background for employing RF in pasteurization of in-shell eggs. This study showed that if careful process parameter optimization and meticulous equipment design is done, RF heating can be successfully employed to pasteurize in-shell eggs.

Three hexagonal patch antennas are designed for circular polarization and experimentally validated. These antennas are labeled; simple hexagonal patch, hexagonal patch with slotted ground and hexagonal patch with parasitic element. The measured impedance bandwidths of the three antennas are 2% for the simple patch, 5.2% for the patch with slotted ground and 6.35% for the antenna with parasitic element. The axial ratio (measured) obtained is 4.73% for the patch with slotted ground and 3.33% for the hexagonal patch antenna with parasitic element. The measured radiation patterns of these antennas are found to be in good agreement with the simulated radiation patterns. The average gain of all the three antennas is also evaluated. A frequency selective surface (FSS) is proposed with dimensions smaller than that of a conventional FSS structure. The measured gain improvement with the proposed FSS is around 3 dB in the operating band.

In this paper we present designs of fibersμ having non-zero positive, non-zero negative and near-zero ultra-flattened dispersion with small dispersion slope and ultra-large effective area over a wide spectral range. The designs consist of a concentric multilayer segmented core followed by a trench assisted cladding and a thin secondary core. The central segmented core helps in maintaining desired dispersion over a wide range of wavelength. The second core of the fiber helps in achieving ultra-large effective area and trench assisted cladding reduces the bending loss. The designs of the fiber have been analyzed by using the transfer matrix method. For positive non-zero dispersion flattened fiber we have optimized dispersion near +4.5 ps/km/nm in the wavelength range 1.46-1.65 μm. Maximum value of dispersion slope of the fiber in above mentioned wavelength range is 0.026 ps/km/nm². In the design of negative non-zero dispersion flattened fiber, dispersion has been achieved near -6 ps/km/nm in the spectral range of 1.33-1.56 μm and maximum value of dispersion slope is 0.048 ps/km/nm². Dispersion and dispersion slope of near zero dispersion flattened fiber lie in the range [0.0039-0.520] ps/km/nm and [(0.0004)-(0.0365)] ps/km/nm² respectively in the spectral range of 1.460-1.625 μm. The near zero dispersion flattened fiber has an ultra-high effective area ranging from 114 μm² to 325.95 μm² in the aforementioned wavelength range, which covers the entire S+C+L-band. These values of mode area are noticeably higher than those reported in literature for flattened dispersion fibers with large mode area. Designed fiber show very small bending loss. We report breakthrough in the mode area of the single mode optical fiber with ultra flattened dispersion and low dispersion slope.

Electrical equipments usually radiate unintended emission which carries characteristic information when running, such as emanation from computers monitors, keyboards and other components, this emanation can be possibly used to reconstruct the source information. Most of the experiments related to this area are carried out inside a semi-anechoic chamber, and measurement out of it may not be considered to be optimal, because the data captured are usually not sufficient. Yet in this study, we take LCD monitors as typical examples and find that characteristics significantly differ between products, parameters such as the magnitude and spectrum were measured under normal environment. We take the PCB traces as antennas and acquire the raw signal directly near the antenna and extract the parameters to use as input to support vector machine (SVM) which was trained to identify the emanating source(LCD monitors). In this study, the method was tested using the emission captured from one Samsung (SyncMaster E1920) and two LG (L1753s) monitors, and a laptop(ACER Aspire 5542). The SVM was able to classify the source of signals with 98.9510% accuracy while using emission that captured from the running monitors.

Due to the increasing number of applications in engineering design and optimization, more and more atention has been paid to full-wave simulations based on computational electromagnetics. In particular, the finite-element method (FEM) is well suited for problems involving inhomogeneous and arbitrary shaped objects. Unfortunately, solving large-scale electromagnetic problems with FEM may be time consuming. A numerical scheme, called the dual-primal finite element tearing and interconnecting method (FETI-DPEM2), distinguishes itself through the partioning on the computation domain into non-overlapping subdomains where incomplete solutions of the electrical field are evaluated independently. Next, all the subdomains are ``glued'' together using a modified Robintype transmission condition along each common internal interface, apart from the corner points where a simple Neumann-type boundary condition is imposed. We propose an extension of the FETI-DPEM2 method where we impose a Robin type boundary conditions at each interface point, even at the corner points. We have implemented this Extended FETI-DPEM2 method in a bidimensional configuration while computing the field scattered by a set of heterogeneous, eventually anistropic, scatterers. The results presented here will assert the efficiency of the proposed method with respect to the classical FETI-DPEM2 method, whatever the mesh partition is arbitrary defined.

In this paper, a new numerical method of calculating rectangular busbar impedance is proposed. This method is based on integral equation method and partial inductance theory. In particular, impedances of shielded and unshielded three-phase systems with rectangular phase and neutral busbars, conductive enclosure, and use of the method are described. Results for resistances and reactances for these systems of multiple rectangular conductors have been obtained, and skin and proximity effects have also been taken into consideration. The impact of the enclosure on impedances is also presented. Finally, two applications to three-phase shielded and unshielded systems busbars are described. The validation of the proposed method is carried out through FEM and laboratory measurements, and a reasonable level of accuracy is demonstrated.

For the coaxial outer corrugated resonator, dispersion equations of TE and TM modes are derived by the surface impedance theory, and the first order transmission line equations with mode coupling coefficients are deduced by means of the transmission line and coupling wave theory. According to them, resonant frequency, diffractive quality factor and field profile of geometry of the eigen-mode about the coaxial outer corrugated resonator can be calculated. The effect of outer slot depth, tooth width as well as asymptotic angle of outer conductor and slope angle of inner conductor on resonant frequency and quality factor can be researched. Results show that changes of the outer slot depth and tooth width slightly affect the field frequency and quality factor and that the changes of the asymptotic angle of outer conductor and slope angle of inner conductor almost do not affect field frequency, but greatly affect quality factor.

The theory of even/odd mode based dual composite right/left handed (D-CRLH) unit cells is developed, and a unified modeling approach based on stubs is presented. The theory shows that these unit cells will have left-handed behavior if the even and odd mode corresponding stubs have dual behavior. Several unit cells are investigated. The proposed models agree with EM simulations. Experimental results confirm the presented theory.

An ultra-wideband (UWB) bandpass filter (BPF) with application oriented triple notches and simultaneously suppressed stopband is proposed. Implementing complementary split ring resonator (CSRR) and novel complementary meandered folded split ring resonators (CMFSRR) shaped defected ground structures (DGS) in the ground of proposed structure generates the triple notch in the UWB passband. The notch positions are functions of CSRR/CMFSRR profile dimensions. Stopband is suppressed using the dual attenuation poles generated by the double equilateral-U (DEU) shaped DGS. An approximate lumped equivalent circuit model of the proposed filter is presented. Measured results obtained are in good agreement with the equivalent circuit model and full wave electromagnetic (EM) simulation. The filter is small in size with an overall area of 26.06 mm × 11 mm.

In this paper, a novel circular-hexagonal fractal antenna is investigated for super wide band applications. The proposed antenna is made of iterations of a hexagonal slot inside a circular metallic patch with a transmission line. A partial ground plane and asymmetrical patch toward the substrate are used for designing the antenna to achieve a super wide bandwidth ranging from 2.18 GHz to 44.5 GHz with bandwidth ratio 20.4 : 1. The impedance bandwidth and gain of the proposed antenna are improved than the recently reported antennas which make it appropriate for many wireless communications systems such as ISM, Wi-Fi, GPS, Bluetooth, WLAN and UWB. Details of the proposed antenna design are presented and discussed.

In this paper, some optimal programs have been proposed through the analyses of transient grounding resistance (TGR) to reduce the grounding resistance using the finite-difference time-domain method. First, the TGR of various electrode types, lengths and sectional programs is studied, and it is found that a flat bar is the most financially efficient conductor to be used as grounding electrode. Enlarging grounding electrode length can reduce grounding resistance when it is shorter than the effective length, but the reduction effect declines as the length increases. Additionally, a series of small electrodes would lead to a much lower resistance than a single large one. Second, it is demonstrated that locally improving the soil near the grounding system is an efficient way of reducing the grounding resistance. Improving a limited area soil surrounding the lifting line would reduce the peak resistance significantly, while local enlarging electrodes surrounded soil conductivity can reduce the grounding system steady resistance obviously.

Electromagnetic interference (EMI) of the power supply system in electric vehicles will seriously affect the safety of the vehicle and passengers' health. So a model of power supply system is presented to analyze its conducted EMI in the paper. This model shows the effects of paralleled interleaving DC/DC converter, which contains the new circular current EMI characteristics. Also, a novel power battery model is established considering both the energy dynamic processes and the high frequency features. Firstly, the power electronics devices are studied as the most important part of the DC/DC converter. Then, the equivalent model of the paralleled interleaving DC/DC converter is set up to express the interference source features. Also, the power battery, which is the main energy storage equipment in electric vehicles, is modeled as EMI propagation paths. Furthermore, loads of the power supply system, such as lead acid battery and low voltage devices, are investigated to evaluate their immunity. Finally, the system model is established. The system EMI is analyzed to get their generating causes, time domain and frequency domain characteristics based on both simulations and experiments.