In this paper, we provide a new architecture by using the programmable graphics processing unit (GPU) to move all electromagnetic computing code to graphical hardware, which significantly accelerates Graphical electromagnetic computing (GRECO) method. We name this method GPUECO. The GPUECO method not only employs the hidden surface removal technique of graphics hardware to identify the surfaces and wedges visible from the radar direction, but also utilizes the formidable of computing power in programmable GPUs to predict the scattered fields of visible surfaces and wedges using the Physical Optical (PO) and Equivalent Edge Current (EEC). The computational efficiency of the scattered field in fragment processors is further enhanced using the Z-Cull and parallel reduction techniques, which avoid the inconsistent branching and the addition of the scattered fields in CPU, respectively. Numerical results show excellent agreement with the exact solution and measured data and, the GPUECO method yields approximately 30times faster results.

Abstract-In this paper, a compact band-notched UWB planar antenna with Transmission-Line-fed is presented and I'm using a new technique by etching a narrowband resonance H-shape slot in the ground plane of the antenna. This antenna is capable reducing the interference at the WLAN bands by eliminating the 4.85-6.17 GHz band. The proposed antenna has compact size of 16 × 22mm² including the ground plane and because of miniature dimensions, good radiation patterns with monopolar characteristics are obtained in the frequency band of interest i.e., at least 10 dB isolation exists between co-polarization and cross-polarization. The gain is suppressed very well in WLAN bands. The maximum suppression is in 5.4 GHz that is 13.6 dB less than the gain of normal antenna.

The first calculation of mobility and conductivity between source and drain as function of gate voltage in a δ-doped Field Effect Transistor is presented. The calculation was performed with a model for the δ-FET that was shown in [1]. The mobility was calculated using a phenomenological expression that was presented in [2]. That expression does not have empirical form, neither empirical parameter. For the first time a phenomenological expression of the conductivity is presented, which is derived from the mobility expression. The conductivity shows three different regions: a parabolic region and two linear regions. The parabolic region represents the region at which the conduction channel begins to close. On the other hand, the mobility shows a more different behavior. In the mobility there are four regions. These regions correspond to the disappearance of the different conduction channels that form the subbands of the deltadoped quantum well. The different behavior between mobility and conductivity relies on the depletion of the delta-doped quantum well as the gate potential grows.

In this paper, complementary spilt ring resonator (CSRR) is applied to design harmonic suppression microstrip rat-race and branch-line coupler. As the CSRR cell is etched on the ground plane of the substrate, the frequency selective properties have a considerable relation with its geometry parameters, which has been analyzed detailedly. As demonstration, a rat-race and a branch-line coupler are designed and fabricated using conventional printed-circuit board fabrication process. The proposed couplers show the performance as good as that of the corresponding conventional structures, but deep harmonic suppression in addition. The design and simulation have been performed using full-wave EM TOOLS ADS Momentum.

Combined ground penetrating radar and metal detector equipment are now available (e.g., MINEHOUND, ERA Technology- Vallon GmbH) for landmine detection. The performance of the radar detector is influenced by the electromagnetic characteristics of the soil. In this paper we present an experimental procedure that uses the same equipment for the detection and calibration by means of signal processing procedures for the estimation of the relative permittivity of the soil. The experimental uncertainties of this method are also reported.

In this paper, the numerical simulations of photoinductive imaging (PI) method have been performed using the finite element method (FEM) with the 2D transient to characterize corner cracks at the edge of a bolt hole. The PI imaging results have higher spatial resolution in the area of the defect in 2D models as compared with the conventional eddy current (EC) images. The FEM simulation results of 0.5-mm rectangular defects are showed and analyzed. The dependencies of PI signals on EC frequencies and temperature of the thermal spot are also examined. The results demonstrate that the PI method is applicable to examine the geometric shape of corner cracks.

In this work tight binding calculations in Be δ-doped GaAs quantum wells with an electric field applied along the [001] growth direction are presented. The Stark shifts of the hole electronic states for different impurity concentrations and electric field strengths are calculated. The δ-potential is treated as an external potential following the approach described earlier. A comparison with Stark effects in rectangular and graded-gap quantum wells is made.

In this work, CPW-to-stripline (SL) vertical via transitions using gradually stepped vias and embedded air cavities are presented for V-band LTCC System-on-Package (SoP) applications. In order to reduce radiation loss due to abrupt via discontinuities, gradual via transitions are proposed and investigated. In addition, in order to reduce increased parasitic shunt capacitance due to stepped via structures, air cavities are embedded below the transition vias. Using a 3-D EM simulation tool, the proposed transitions are designed and analyzed, compared to the conventional transition. Three-segment transmission lines (CPW-SL-CPW) in 7-layer LTCC dielectrics were fabricated and measured. The two stepped via (STV2) transition embedding air cavities shows an insertion and return losses of 1.6 dB and below -10 dB, respectively, over 60 GHz. The transition loss per one STV2 transition is 0.7 dB at 60 GHz.

A hybrid method of boundary element method (BEM) combined with conformal transformation (CT) is presented to calculate the capacitance of the unscreened slab lines. Conformal transformation transforms the infinite boundary boundary-value problem with the unscreened slab line into a finite boundary one that can be solved by the BEM, then the capacitance of the unscreened slab line is obtained by the BEM. Three representative computational examples, unscreened cylindrical single-bar slab line, unscreened rectangular single-bar slab line and unscreened cylindrical-bar coupled slab line, are given to validate the accuracy and efficiency of the CT-BEM hybrid method.

Polarimetric SAR Interferometry can be used for parameter inversion of ground. An appropriate model is of most importance for parameters inversion. This paper derives a series of scattering model that can be used for parameter inversion of forestry area, such as RV, RVoG, OV and OVoG. These models can reveal the characteristics of forestry area as well as establish the relationship between observed data and parameters of test area. Finally, a multi-layer random scattering model that can be used for parameter inversion of forestry area containing a man-made target is derived. An improved model is examined by the simulated data of the singlebaseline polarimetric SAR interferometry. The result turns out that the improved RVoG scattering model is correct.

A new band-pass narrow-band, miniaturized and single resonance within a wide range of frequency band frequency selective surface structure with lumped capacitors suitable for low frequency and narrowband waveguide filter applications is presented. The filter structure consists of five unit cells in one direction with notch square ring elements each consists of two lumped capacitors placed on the transverse plane of the rectangular waveguide. To reduce the simulation time in design procedure, split-field update FDTD method is used for the analysis of the unit cell of the analogous infinite frequency selective surface at different oblique incidence of plane waves to predict the FSS performance in the waveguide. As an application, a waveguide filter has been designed to be used in an easy to fabricate and inexpensive S-band band-pass filter. By using lumped capacitors, several undesirable higher order resonance frequencies near the dominant resonance frequency are eliminated and the waveguide filter dimensions are reduced considerably in one direction compared with the analogous waveguide filter without lumped capacitors.

In this paper, we propose a low complexity receiver structure for Single-input Multiple-output (SIMO) downlink cyclic prefix CDMA (CP-CDMA) systems. It employs an interference cancellation scheme to suppress the interference caused by the multipath fading channel. Also, the proposed scheme is developed for Multiple-input Multiple-output (MIMO) CP-CDMA system. All filters in the proposed receiver are implemented in the frequency domain. The performance of the proposed receiver is studied and compared. Our results show a large performance improvement when using such an interference cancellation scheme relative to the rake receiver, and frequency domain Equalization (FDE).

Radiation of a Hertzian dipole in a short-ended conducting circular cylinder with narrow circumferential slots is presented. Modematching and Fourier transform were utilized to derive a system of simultaneous equations for modal coefficients. Computations were performed to confirm the fast convergence of the series solution.

A novel uni-planar electromagnetic Band Gap (EBG) structure incorporated with inter-digital capacitor and meandered line inductor (ML-ID-EBG) is presented, this novel structure significantly enlarges the fringe capacitance to reduce sized cells, as well as increases the equivalent inductance to widen the relative bandwidth. Its design is detailed in this paper, and several experimental results are presented, the improved properties of the proposed ML-ID-EBG are examined, as compared with a conventional UC-EBG and a novel EBG incorporated only with inter-digital capacitor (ID-EBG).

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 are used for the EM wave analysis. The objective of this study is to decrease or increase the Radar Cross Section (RCS) in an ultra wide band width. The optimization is based on the Method of Least Squares (MLS), employing a novel combination of the Genetic Algorithm (GA) and Conjugate Gradient (CG), where the global search for the minimization point is performed by GA and the local search is done by CG, which greatly speeds up the search algorithm. The behaviors of various combinations of common materials and metamaterials for reduction of RCS are studied. Furthermore, the procedures for selection of correct signs for metamaterial parameters, namely ε, μ, k and η are presented.

An ultra-wideband (UWB) U type monopole antenna fed by a coplanar waveguide (CPW) is proposed. It has low profile and very compact size (14.48mm×28.74mm×0.8 mm). It provides an wide impedance bandwidth ranging from 3.08 GHz to about 12.75 GHz adjustable by variation of its parameters, such as the relative permittivity and thickness of the substrate, width, and feed and ground plane dimensions. Parametric study is presented. Details of the proposed ultra-wideband design are described. Simulation results are presented and discussed in this paper.

The adiabatic parameter dynamics of non-Kerr law optical solitons is obtained in this paper by the aid of soliton perturbation theory. The various kinds of perturbation terms that arise exhaustively in the context of optical solitons are considered in this paper. The new conserved quantity is also used to obtain the adiabatic dynamics of the soliton phase in all cases of non-Kerr laws studied in this paper. The non-Kerr law nonlinearities that are considered in this paper are power law, parabolic law as well as the dual-power law.

A tunnel diode integrated E-shaped patch antenna is proposed and analyzed using equivalent circuit concept. It is found that bias voltage of tunnel diode controls the performance of the antenna. Various tunable frequency bands are obtained by selecting suitable bias voltage while antenna topology remains unchanged. Bandwidth of the tunnel diode integrated patch improves to 40.26% over the 32.58% bandwidth of the patch. The radiation pattern also varies with bias voltage and a considerable improvement in beamwidth is observed however radiated power remains almost same.

This paper presents a square cylindrical monopole antenna easily fabricated using a cross-shaped metal plate for wideband omnidirectional operation. A prototype of the proposed antenna with a cross-sectional area of 8 × 8mm² is implemented, and the antenna provides a wide operating bandwidth of about 7.5 GHz (1.8-9.4 GHz here), making it very promising for WMAN operation with the 802.16e standard in the 2 to 6 GHz. In addition, over the operating bandwidth, the antenna shows very good omnidirectional radiation patterns.

The estimation of the directions-of-arrival (DoAs) of multiple signals is a topic of great relevance in smart antenna synthesis and signal processing applications. In this paper, a memory-based method is proposed to compute the maximum likelihood (ML) DoA estimates. Such a conceptually-simple technique is based on the datasupported optimization (DSO) and the estimation of signal parameters via rotational invariance technique (ESPRIT), but fully exploits a memory mechanism for improving the estimation accuracy especially when dealing with critical scenarios characterized by low signal-tonoise ratios (SNR) or/and small number of snapshots. Simulation results assess the potentialities and limitations of the proposed approach that favorably compares with state-of-the-art methods.