A regular cross terms algorithm is derived for the parameter estimation of the multi-component polynomial phase signals in additive white Gaussian noise. The basic idea is first to separate its phase parameters into two sets by nonlinear procedures£¬and then each set has half of the parameters in its auto-terms. Furthermore, using two linear transforms to deal with the two signals respectively, the phase coefficients of cross terms can be regulated for the identification and elimination of false peaks caused by the cross terms. Simulations are presented to illustrate the performance of the proposed algorithm.

This work deals with the inverse source problem starting from the knowledge of the radiated field in the near field zone. The inverse problem is stated as the inversion of a linear integral equation and the Singular Value Decomposition (SVD) is exploited as an analysis and inversion tool. In particular, here, we deal with a 2D geometry and aim at comparing the features of the inverse problem in dependence on the nature of the source (electric or magnetic).

A one-dimensional electromagnetic bandgap (1-D EBG) ground plane was designed and characterized. The 1-D EBG ground plane, composed of metal patches, metal lines, and a ground plane, has in-phase reflection characteristics when the polarization of the incident electromagnetic waves is parallel to the direction of the EBG unit-cell array. The proposed 1-D EBG ground plane was applied to the design of low-profile directive dipole antennas. The radiators of the designed antennas could be placed very close to the 1-D EBG ground plane without noticeable performance degradation of the antennas. In particular, the dipole antenna designed with the 1-D EBG ground plane and directors has higher directivity and a better F-B (front-to-back) ratio as compared to a conventional dipole antenna backed with a normal ground plane.

In this paper, tunable single-negative (TSNG) metamaterials based on microstrip with varactor diodes loading are investigated. By tuning the external voltage, our structure can provide either an epsilon-negative or a mu-negative band gap, with varying gap width (the ratio of bandwidth to center frequency can be from 0 to over 100%) and depth (from 0 dB to about -30 dB). Moreover, the tunneling mode in a heterostructure constructed by epsilon-negative and TSNG metamaterials is also studied. The results show that its transmission, Q-factor, and electromagnetic localization can also be controlled conveniently. All these properties make our structure promising to be utilized as a practical switching device, or a suitable platform for the study of nonlinear effect in metamaterials.

The paper deals with a method to measure the unknown impedance of metamaterial antenna made in Composite Right/Left-Handed (CRLH) Co Planar Wavegiude (CPW) technique for the millimeter wave frequency domain. The method uses a measurement setup made of a high frequency vector network analyzer (VNA) and an on-wafer characterization equipment. The measurement procedure consists in placing the probe-tip of the on-wafer equipment and to move it along the feedline of the antenna radiating structure until the minimum values of the return loss is reached. Using the facilities of the on-wafer equipment (micrometric screws to move the probe-tips) and knowing the geometrical dimensions of the antenna structure, the dimension and the position of an equivalent open-circuit matching stub are obtained. Then, using relationships derived from the transmission lines theory, real and imaginary parts of the unknown antenna impedance are computed.

A method to enlarge the omnidirectional photonic bandgaps (PBGs) has been presented in the one-dimensional photonic crystals by sandwiching a superconductor layer between two dielectric materials to form a one-dimensional ternary periodic structure. The angle- and thickness-dependence of these PBGs have been investigated in detail, and then the thermally-tunability of these omnidirectional PBGs by controlling external temperature of the superconductor is discussed. It is shown that these omnidirectional PBGs can be extended markedly in the one-dimensional ternary photonic crystal and the gap width or the wavelength range can also be tuned by varying external temperature.

In this work, a novel multi-carrier Tx-Rx system based on rationally synchronized oscillators to be used in RF-source localization applications is presented. The Tx subsystem is composed by two rationally synchronized oscillators, with different operation frequency, which share the reference signal. This signal is transmitted together with the one generated by the oscillators. In the Rx subsystem, the reference signal is provided by an oscillator which is synchronized with the received reference signal. According to the simulation results, with the proposed approach, the determination of the relative phase variation suffered by the transmitted signals, due to the propagation channel, can be achieved with an error less than 0.6^o. It is also shown that the dynamic response of the system can be optimized by properly selecting the operation point of all oscillators.

Achieving and controlling highly selective response in an electronic component could be particularly beneficial for numerous practical applications. In this work, we consider a simple configuration of a discontinuous parallel-plate waveguide with a narrow rectangular ridge filled with axially anisotropic material. The formulated boundary value problem is rigorously treated with help from mode matching technique. The variables with respect to which the device exhibits highly selective behavior and the parameters through which the regulation of sharp variations becomes possible, have been identified. Several graphs demonstrating these properties are analyzed and discussed.

In this paper, a novel and computationally efficient algorithm which combines Array Signal Processing (ASP) approach with Fourier Optics (FO) is developed in the realm of gain enhancement achieved by placing Uniplanar Compact-Photonic Band Gap (UC-PBG) structures on top of microstrip antennas. The proposed scheme applies FO to the well-known sampling theorem borrowed from Digital Signal Processing (DSP) analysis in the framework of ASP approach which we refer to as the FDA algorithm. The FDA algorithm is suitable for lossless UC-PBG structures with 1-D, 2-D and 3-D lattice of canonical geometrical apertures, such as circular, octagonal, hexagonal, and square. In order to validate the proposed approach, two different UC-PBG structures of octagonal and circular apertures are considered at 2.6 GHz. The UC-PBG structures under consideration consist of two layers positioned above a microstrip antenna; each layer is an array of 9×9 apertures separated by half of the focal length distance of the lens in the near-field of the microstrip antenna. The performance of the microstrip antenna with and without the UC-PBG is reported using numerical simulations performed using CST Microwave Studio (CST MWS) based on the Finite Integration Technique (FIT). The radiation patterns and directivity of the microstrip antenna based on UC-PBG structures are evaluated using the proposed FDA algorithm and validated against numerical results obtained from CST MWS where an excellent agreement is found between the FDA algorithm and the 3-D full wave simulations. The UC-PBG structure of octagonal apertures provides a remarkable enhancement in the bore-sight gain of about 7.8 dBi at 2.6 GHz with respect to that obtained from the conventional microstrip antenna, while the circular apertures provide gain enhancement in excess of 10 dBi above the gain of the same microstrip antenna.

We theoretically find that a bi-layer structure composed of two kinds of dispersive metamaterials can possess an asymmetric reflection spectrum due to Fano-type interference between a discrete reflection resonance and a broadband strong reflection. The discrete reflection resonance appears at the frequency around which the dispersive permeability is near to zero at oblique incidence. Based on analytical and numerical analysis, the asymmetric factor in the Fano-type reflection is found to be linked with the angle of incidence.

A novel hybrid design of Bluetooth and UWB antenna with dual band-notched functions is proposed. The proposed antenna structure consists of a microstrip-fed main patch and electromagnetically coupled parasitic patch with arc-shaped strips, achieving Bluetooth and UWB performance. Additionally, the split ring resonator (SRR) slot etched on the main patch and the square patch close to microstrip feedline are aimed to obtain dual notched bands. The numerical and experimental results exhibit that the designed antenna operates over the wide frequency band from 3 to more than 12 GHz, while showing the extra resonant mode at 2.4-GHz Bluetooth and the band rejection performance at 3.5-GHz WiMAX and 5.2-GHz WLAN.

We present the GPUs computation acceleration for a very recurrent electromagnetic problem which is the calculation of the field radiated by electric dipoles in a multilayer structure (Green's tensor in stratified background), based on the well-known Sommerfeld integrals. Using an optimized parallelization scheme, huge computation acceleration is obtained. Applications of such a work are very broad, especially for the modeling of stratified light emitting devices, or as a building block for the calculation of optical scattering by complex shape structures, when using methods as discrete dipole approximation (DDA) or method of moments (MoM) for example.

This paper presents the results of Boundary Element Method (BEM) numerical procedures of voltages distribution between transmission lines in order to investigate the theoretical corona discharges. The algorithm of the voltage distributions are coded in Mathematica studying size of the system under controlling Neumann and Dirichlet boundary conditions. Conducting experimental work at a high voltage (HV) is potentially very dangerous. Therefore, simulation is a vital research approach, and computer modeling offers significant advantages to estimate optimal calculation over established system to prevent dangerous voltage and not to exceed the corona voltage. In this paper, the BEM results are verified with Finite Element Methods (FEM) which is coded in Mathematica too.

In this paper, the performance of conventional Uniplanar Compact Photonic Band Gap (UC-PBG) structures is investigated under different bending extents. The structure under study is operated as an Artificial Magnetic Conductor (AMC) in which performance is mainly characterized by its resonant frequency and bandwidth. Modelling and numerical analysis have been carried out using CST Microwave Studio simulation software which is based on Finite Integration Technique (FIT). Results show that different bending extents affect the AMC's performance which is specified by a shift to higher resonant frequencies and bandwidth degradation when the degree of bending is increased. Furthermore, we point out some important simulation tips to avoid inaccurate and/or invalid results. This type of study is important to evaluate the performance of such structures for conformal applications. To the best of the authors' knowledge, such type of systematic study is being reported for the first time.

In this paper, we use the Bloch theorem and transfer matrix method to calculate the dispersion relation of a ternary 1D photonic crystal with left-handed materials. Then, we obtain the total omnidirectional reflection band gaps of this structure. We demonstrate that the omnidirectional reflected frequency bands are enlarged in comparison with ordinary materials with positive index of refraction.

In this paper, we present a cylindrical shaped-reflector antenna which is spatially fed by an off-set linear feed array to form complex beam patterns. The linear feed array consists of twelve microstrip patch elements and forms a flat-topped beam pattern with a beam-width of ±45° in the azimuth plane. The vertical curve on the cylindrical reflector with the linear feed array is shaped to form a cosecant beam pattern within the range of -5° to -25° in the elevation plane. By using the proposed design procedure to form complex beam patterns, a hybrid antenna with a cylindrical reflector aperture of 140 cm x 50 is designed to be operated within the IMT 2000 service band, and a prototype antenna is also fabricated. Its electrical performance is measured and compared with simulation results.

This work presents extremely compact dual-mode and dual-band bandpass filter designs based on dual-resonance composite resonators developed by using integrated passive device (IPD) technology on a glass substrate. A dual-mode bandpass filter is also devised using a symmetric composite resonator with a perturbation element of grounding inductor to determine the filter bandwidth. Additionally, a feedback capacitive coupling path on the proposed dual-mode filter is implemented to produce three transmission-zero frequencies in the stopband. Furthermore, the proposed dual-band bandpass filter is designed in a high-density wiring transformer configuration with magnetic and electric mixed coupling. In addition to individually determining the fractional bandwidth of dual passbands, the magnetic and electric mixed coupling provides multiple transmission zeros to enhance the isolation between the two passbands and greatly improve the stopband rejection.

A coherent imaging system images a frame or an object onto a changing diffuser and projects the resulting pattern which generally contains speckles. Using a spatial light modulator (SLM) as the changing diffuser, the speckles in the pattern are suppressed without the need for any other mechanisms. With $M$ random phasor arrays being displayed in the SLM during the integration time of a detector, a suppression factor (C_f) of speckles, 1/√M, is achievable in the projected pattern, which is the sum of the intensity of M uncorrelated patterns. This paper shows both theoretically and in simulations that the C_f of the sum pattern was considerably reduced when two elementary patterns with fully developed speckles were negatively correlated. With the correlation coefficients of the elementary patterns found at [-0.3, -0.25], the C_f of the sum of 10 negatively-correlated speckle patterns was 48% lower than the C_f of the sum of 10\,uncorrelated speckle patterns. The negatively correlated patterns can be implemented using spatial light modulators or diffractive optical elements, and are used to suppress speckle noise in digital holography, laser projection display, and holographic display projections with relatively high efficiency.

This paper presents an inside-out axial-flux permanent-magnet brushless DC motor optimized by Finite Element Analysis (FEA) and Genetic Algorithm (GA) that uses sizing equation. The double-sided slotted-stator designed TORUS motor has sinusoidal back EMF waveform and maximum power density. The GA obtained the dimensions that gave the motor its highest power density. Field analysis of the dimensions was then put through FEA, to obtain and re-optimize the motor's characteristics. Possible design parameters were investigated via use of Commercial Vector Field Opera 14.0 software used in three-dimensional FEA simulation and of MATLAB 2010a in GA programming. Techniques such as modifying winding configuration and skewing the permanent magnets were explored to achieve the most-sinusoidal back-EMF waveform and minimized cogging torque. The desired technical specifications were matched by simulation results of the 3D FEA and the GA. The FEA and the GA simulation results comparison of the flux density in different parts of the designed motor at no-load condition agreed well.

A novel dual-mode bandpass filter (BPF) using stub-loaded defected ground open-loop resonator is proposed in this article. Defected arrow-shaped stub is loaded to a defected ground open-loop resonator, and two non-degenerate modes are excited for dual-mode characteristics. Based on even- and odd-mode theory, dual-mode characteristics of the resonator is analysed. Design equations for the defected-ground resonator are investigated. A two-pole dual-mode bandpass filter operating at 2.4 GHz with fractional bandwidth of 7.97% is designed, fabricated, and measured. Good agreement between simulated and measured results verifies the validity of this design methodology.