ABSTRACT This paper presents an efficient time-domain analysis of RF/microwave nonlinear circuits in the presence of the incident uniform plane wave. In this paper, a set of differential equations, including the linear equations due to incident field coupling and nonlinear state equations for the active part of the circuit, are derived and simultaneously solved using the finite difference time domain

A circularly polarized (CP) scanning phased array antenna based on circular polarizer is proposed. An efficient technique is developed to introduce the novel scheme of the designed patch antenna and circular polarizer, which are coupled with a small gap. The new approach of fission transmission of electromagnetic (FTEM) wave is developed to transform linear-to-circularly polarized waves. The designed

In this paper, compact Ultra-Wide Band (UWB) 1:2:1 unequal split modified Bagley Power Divider (BPD) using Non-Uninform Transmission Lines (NTLs) theory is designed and tested. Based on this theory, 42.44% and 31.1% size reductions are obtained in the lower and upper λ/4 Uniform Transmission Lines (UTLs) in the first and second sections of the proposed divider. To evaluate the effect of the divider’s

ABSTRACT Modern aircraft, ship, and other systems have different consequences when faced with the own and external radio frequency, lightning and other electromagnetic environments (EME) radiation, that is called electromagnetic environmental effects (E3). In this paper, a new method of system-level E3 quantitative control is proposed. A two factor E3 impact degree model composed of susceptible receptor

Metamaterial properties of a novel half-mode CRLH unit cell are investigated and hence a compact dual-wideband antenna is designed using an array of four unit cells. The negative refraction of the metamaterial cell is utilized to miniature the antenna. A via-free open stub, in combination with an interdigital capacitor, makes the half-mode CRLH unit cell. The proposed antenna operates at both C-band

Our present work is concerned with the study of a semi-infinitely long, conducting solid with a cavity in cylindrical form in the context of magneto-thermo-elastic diffusion with two-temperature and three-phase-lag effect. The medium we have considered here is supposed to be initially quiescent. The material is assumed to be made of an isotropic homogeneous thermo-elastic material and put in a magnetic

This paper describes the integrated use of two design strategies for controlling the permittivity and permeability of a transformation electromagnetics two-dimensional cloak. This hybrid process permits more freedom in the choice of the constitutive properties, which could simplify the implementation with metamaterials. Because simplicity of materials and scattering performance are inherently conflicting

Fractal geometry antennas are much sought after in present scenario of wireless communication due to ever increasing demand for high gain, wide bandwidth, low cost, compact size and easily deployable antennas. An ultrawide band monopole antenna using compact hexagonal-square shaped fractal geometry is proposed here, which nearly fulfils the above demands. The fractal geometry is introduced by iteration

A conceptual Kriging surrogate model (KSM) for the computational analysis and design of H-shaped microstrip antennas (HMAs) is proposed in this study. A dataset contains 216 simulated HMAs with different physical/electrical parameters of the HMAs and the respective resonant frequency (RF) values are employed in construction and test processes of the KSM. The performance of the KSM is tested and verified

ABSTRACT This paper presents a simple microwave non-destructive method to assess the uniformity of fiber distribution in the steel fiber reinforced concrete (SFRC). To simplify the assessment, only the amplitude attenuation information is needed, but no phase information is required. The assessment can be achieved by means of the relationship between the attenuation constant and the quantity of steel

The theoretical analysis of hybrid surface wave propagation at chiral-plasma planar interface is presented in this manuscript. The dispersion relation is obtained for the proposed structure by applying boundary conditions at the chiral-plasma interface. The characteristic of hybrid surface wave can be tuned by changing the plasma frequency, plasma collisional frequency, and chirality parameter. It

This paper presents an L-strip fed compact wearable dual wide band circularly polarized textile antenna (DWCPTA) with a pair of parasitic elements and dual wide band operations at frequencies 2.45 and 5.80 GHz for industrial, scientific and medical (ISM) band applications. The antenna is printed on top of denim (jeans) substrate having dielectric constant 1.7 and thickness of 1.43 mm with wide slot

This paper develops an unfamiliar modelling of printed circuit board (PCB) interconnect behaving as HH-tree. The developed model is based on the tensorial analysis of networks (TAN) formalism. The HH-tree is implemented with the equivalent LC-network based on Hammerstad-Jensen modelling. The unfamiliar TAN methodology is described by starting from the equivalent graph topology. The HH-tree TAN model

This paper presents a new technique to reduce radar cross-section (RCS) of dual-band antennas. In order to show that the proposed method can be applied in various types of monopole antennas, two different patch antennas are designed one of which is fabricated. The primary model of the fabricated antenna without modification is composed of a circular radiator with two pairs of T-shaped strips. To reduce

ABSTRACT This paper presents an ultra-wideband and highly miniaturized dual-mode Wilkinson power divider fabricated using thin film integrated passive device (TFIPD) technology for GSM band (0.9 GHz). The four quarter-wavelength lines of conventional two-section Wilkinson power divider are replaced with π-type transformer. In addition, a RC filter is introduced at the input port to minimize the return

In this paper, a quasi-optical mode converter for terahertz imaging is presented. This design is based on a 0.22 THz TE03 gyrotron oscillator. It includes a Vlasov launcher, an elliptical reflector and a parabolic reflector, which is used to convert TE03 cylindrical waveguide mode to a Gaussian-like beam. The quasi-optical system is analyzed in terms of geometric optics theory and the vector diffraction

The problem of normal waves in an inhomogeneous dielectric layer is reduced to a boundary value problem for the longitudinal components of the electromagnetic field in Sobolev spaces. Nonhomogeneous filling and entering of spectral parameter in transmission conditions lead to the necessity of special definition of solution to the problem. We formulate the definition of solution using variational relation

A novel approach of multiband real permittivity and permeability estimation of the magnetic composites using a modified under coupled multimodal (TE10p) substrate integrated waveguide (SIW) cavity is presented. The proposed schemes allow the accurate wideband microwave characterization of the magneto-dielectric composites by using the higher-order modes of the designed SIW cavity. The analytical closed-form

In this study, an adaptive pattern nulling approach of half-wave dipole uniform linear arrays (DULA), inspired by binary bat algorithm (BBA)-based beamformers and the phase-only control of array excitation weights, has been proposed. This helps suppress interference with unknown directions in the sidelobe region. Several scenarios have been conducted to investigate the performance of the proposal including

We present techniques for solving the problem of detecting element failures in phased array antennas by using a combination of a single fixed probe and an optimization of element excitations using principles derived from compressive sensing. This departs significantly from conventional techniques where the excitations are held constant and probes are instead moved spatially to collect measurements

This article presents a stack of metal/dielectric lamination absorber shaped as a doubly periodic array of truncated prism. We show how the EM absorption characteristics can be modified through simple changes to the geometric structure of the unit cell. The resultant absorber can be designed to exhibit broadband performance, i.e. 10 dB return loss from 8.2 to 14.2 GHz. We then discuss the angular TE

This work presents two wideband coplanar-waveguide bandpass filters using open-circuited stubs (Design 1) and short-circuited stubs (Design 2), respectively. The electrical lengths of stubs were accurately determined by a phase comparison method. In Design 1, a spurious resonance was found at the high band edge of the passband. The problem was solved by introducing oblique air bridges to ruin the undesired

Introducing compressed sensing theory into the millimeter-wave near-field holographic imaging algorithm, it can break the Nyquist sampling limit, reconstruct the compressed echo signal, and invert the target image. In the reconstruction process, there are defects such as missing target key information, excessive invalid search volume and so on. Aiming at this problem, an adaptive multi-extreme particle

Recently, the defects in Gas-Insulated Busduct (GIB) affect the electric field distribution badly over the spacer length and de-energies the GIB leading to huge loss economically. In this paper, a post type spacer with Functionally Graded Material (FGM) has been designed for a three-phase GIB under protrusion and further electric field stress is minimized by inserting metal inserts. Functionally graded

A proposed three-layered patch antenna array combined with Uniplanar Compact Photonic Bandgap structures (UC-PBG) is presented to avoid non-desired radiations from the feeding structure and to mitigate the surface propagation modes, increasing the radiation efficiency, and reducing the parasitic lobes. The array is fed by electromagnetic proximity, implemented by a stripline network below the radiators

To analyze electromagnetic (EM) transient responses of a buried cable, an accurate and reliable time-domain method is proposed in this paper. The approach is based on the transmission line (TL) second-order telegrapher’s current equation, and the expressions of ground impedance and admittance at higher frequencies are used to obtain the discrete finite-element time-domain (FETD) equations for the cable

Scattering from a grounded chiral slab with rough interface is studied using perturbation theory. A system of equations for zeroth and higher order solution is written, which can be solved to get co and cross polarized scattered and transmitted field components. The zeroth-order coefficients provide the results for the flat case, while the higher order coefficients provide the solution with perturbation

An ultra-thin, multiband, micro-slot based metamaterial absorber is presented in this paper. The proposed unit cell is compact which is in the form of single-layer gold patch-gallium arsenide-ground package, involving four identical micro-slots. Using the micro-slots, the fundamental circular patch gains a multiband resonation skill, and the absorber operates at 1.16, 2.73, and 4.57 THz bands with

In the present article, a fork-shaped UWB-MIMO antenna is designed and experimentally tested to achieve hexa-band rejection characteristics. Initially, the proposed array consists of two fork-shaped radiators and a reduced ground with a vertical stub, designed to cover a large bandwidth from 3.64–12.2 GHz and high port-to-port isolation. Furthermore, each fork-shaped radiator is defected with two U-shaped

A method incorporating Bode–Fano integrals is proposed in this paper to evaluate the potential bandwidth of small antennas and provide a particular strategy for bandwidth improvement. The Bode–Fano theory is applied to the equivalent circuit of small microstrip antennas to calculate the maximum achievable return loss-bandwidth. Results of applying this theory to three types of microstrip antennas in

A dual-beam planar slow wave structure (SWS), named dielectric supported ring-bar SWS is proposed in this paper. The planar SWS is supported by two dielectric rods at the side edges, making it fit for dual sheet beam operation. The high frequency and transmission characteristics of the proposed SWS are investigated. The backward-wave oscillation and higher harmonic waves are effectively suppressed

Collectors are an indispensable part of any vacuum microwave devices where the electron beam – so-called spent electron beam emerged from interaction structure – is collected. Although the first publication on depressed collectors dates back to 1940s, several evolving researches are still being carried out on collectors till date. The incessant publications from researchers all over the globe reveal

Interaction between water and lubrication grease oil is not desirable, but it is not inevitable. The operational life of the machine component is influenced by humid grease oil. Metameterial-based transmission line sensor application is proposed and its operation is validated both numerically and experimentally by inserting grease oil samples in the sample holder. The proposed sensor structure is able

Small-sized gold nanoparticles (∼3nm) coated with Glutathione (GSH) ligand have designed as an active agent in photothermal therapy (PTT). GSH is pH-sensitive surface that have a fast response property to the variation in pH conditions, especially between normal (∼7.4) and cancer cell (6–6.5), that help the evaluation of the target and toxic effect of the cancer rather than normal cells. Results revealed

This paper develops an original circuit theory of energy and data transition. The modelling of signal and energy hybrid receiver (SEHR) is developed. The SEHR topology is described in function of the constituting coupled line (CL) and a transmission line (TL) performed with unfamiliar and arbitrary load values. The equivalent S-matrix versus electrical parameters is established. The analysis of the

Influence of the density of mode spectrum in the gyrotron cavity on the possibility of stable single-mode operation has been investigated for high-order modes. Interaction of the operating mode with its two neighboring satellites, symmetrically spaced in frequency, is analyzed. Some threshold value of mode spectrum density dependent on the beam current is found.

In recent years, the exotic capability of metamaterials to absorb perfectly electromagnetic wave has induced potentially many practical purposes, especially, the rapid growth of 5G/6G telecommunication systems. Therefore, the perfect metamaterial absorbers have been reduced in a fast way to several hundred times smaller than the working wavelength. However, it is still a big obstacle to obtain the

The interaction of a stratified cylinder with an elliptically inhomogeneous plane wave is introduced and also determined through a rigorous theoretical approach. The scattered electromagnetic field by a multilayered cylinder is investigated through an application of the generalized Vector Cylinder Harmonics (VCH) expansion. The exact mathematical model to represent this scenario considers the so-called

The race towards quantum superiority has stimulated efforts on quantum electronics research. This article aims at providing a comprehensive overview of the global research trends and performance in the field, from a bibliometric perspective, using the Scopus database. A total of 10,115 journal articles from the earliest year of publications were retrieved and analysed. Results show that quantum electronics

A new methodology to determine the loss tangent of dielectric planar samples by using electrically coupled resonators is presented. The coupling between the resonators is disrupted by the sample under test (SUT). The proposed methodology is based on the analysis of the equivalent circuit of the sensor in differential and common modes. This work demonstrates that the total quality factor of the electric

Branch-guide energy couplers can be used in the terahertz relativistic sheet electron beam traveling wave tubes (THz-RSBTWT) for high and high frequency microwave radiations. To analyze this type of coupler, a new method based on the phase superposition principle was put forward in this paper. A physical model was developed, which is applicable no matter the coupler width is large or small. The general

In this paper, fundamental properties of solutions to fractional-order (FO) Maxwell's equations are analysed. As a starting point, FO Maxwell's equations are introduced in both time and frequency domains. Then, we introduce and prove the fundamental properties of electromagnetic field in FO electromagnetics, i.e. energy conservation, uniqueness of solutions, and reciprocity. Furthermore, the algorithm

A hybrid effective approach is proposed to focus the intensity of a vector field generated by an arbitrary fixed-geometry array antenna into a target point and keep it bounded elsewhere. To overcome the complexity of the underlying non-convex problem involving a possibly large number of unknowns, we show how the space of possible polarizations can be regarded as a 5-sphere and introduce a nested procedure

This article presents a circularly polarized 4-port Multiple Inputs Multiple Outputs dielectric resonator-based antenna with two resonating bands for WLAN (5.0 GHz) and WiMAX (3.5 GHz) applications. Important attributes of proposed MIMO-DRA are: (i) Bandwidth enhancement is observed due to the use of ring-shaped ceramic material radiator; (ii) Incorporation of rectangular aperture lead to excite the

A triple band-notched monopole antenna with reconfigurable characteristics is designed and investigated in this study for implementation in ultra-wideband (UWB) systems. A conventional rectangular monopole antenna is intended first to accomplish UWB performance characteristics. Further, to obtain triple notched characteristics, three U-shaped slots are etched on the rectangular radiating surface of

We study the transmission spectrum and the band structure of a one-dimensional photonic crystal, made of alternating layers of SiO2 and TiO2 with a GaAs defect layer. The relative permittivity of the GaAs depends on the hydrostatic pressure and the temperature, while its thickness depends only on the pressure. The objective of this work is to apply an external pressure and temperature on the GaAs and

A novel resonant cavity antenna (RCA) with low sidelobe levels over an enhanced bandwidth is presented. Radiation bandwidth of the antenna is increased by using a pair of complementary FSS layers, giving a positive reflection phase over a wide frequency range, as the proposed PRS. Low sidelobes are achieved by lowering the reflection amplitude of the PRS along its length while keeping reflection phase

Transmission of a normally incident plane wave through a pixelated metasurface with meta-atoms made up of graphene-patched and InSb-patched pixels on a silicon substrate was simulated using CST Microwave StudioTM2019 software. This metasurface is electrically controllable due to the graphene-patched pixels, and it is magnetically as well as thermally controllable due to the InSb-patched pixels. A tricontrollable

To improve synthetic aperture radar (SAR) target classification performance, both the feature extraction and classification algorithms are considered. The nonsubsampled contourlet transform (NSCT) is employed to decompose SAR images to generate multi-layer components, which provide more discriminative descriptions for the targets. During the classification, the two-stage sparse representations are

In this article, substrate integrated waveguide (SIW) filter with compact size and wide out-of-band rejection is designed for 5G (sub-6 GHz) applications. To achieve the proposed filter responses, D-shaped resonators oriented face-to-face are etched out on the top layer of SIW. Due to the resonators loading, the filter provides a passband below the cut-off frequency of SIW. This decrease in the operating

In this article, a dual-port aperture-coupled circular fractal antenna array is designed, developed and tested for its usage in 4G, WLAN, radar, satellite and ISS communication systems, covering C-band, X-band and Ku-band of frequencies. The proposed array is designed on two FR-4 substrates (with overall dimensions of 34 × 68.7 × 3.245 mm3) where the upper and lower substrate consists of circular fractal

This paper proposes a novel subwavelength single-layer reflectarray antenna unit cell operating in X-band, composed of double hexagonal rings and a hexapole. This new cell is not sensitive to TE and TM polarizations. Infinite array approach has been used to determine the reflection phase curve. The proposed element has more than 575° linear phase range in 8.5–11 GHz frequency band by varying the radius

The polarization plane rotators located outside the transmission line volume are presented. Their work is based on the excitation of special (‘dihedral') eigen-oscillations in a waveguide object formed by two corrugated flanges with rotational symmetry. Such a topology provides 3D chirality of the composite object at an azimuthal shift of the flanges and rotation of the polarization plane by an arbitrary

The design of transmitting antenna arrays with a modular aperiodic architecture for far-field wireless power transmission (WPT) is addressed in this work. The synthesis of the subarray layout and of the subarrays weights is carried out to maximize the power transmission efficiency, while guaranteeing the full aperture coverage with simple domino-shaped tiles. Two design methodologies, one enumerative

In this paper, we present an improved wave concept iterative process (WCIP) algorithm for the analysis of anisotropic graphene. Then, we use it to investigate a novel type of terahertz microstrip circulator based on graphene. In this algorithm, we propose a new technique for modeling of magnetized graphene layers, which consists of redefining the boundary conditions of graphene in terms of waves and

We present an artificial metasurface comprised of a metallic monolayer having a designed functionality of an Artificial Magnetic Conductor (AMC). The metasurface is designed to operate as a broadband AMC for incident electromagnetic waves polarized in a specific direction, while it works as a pass-band filter for waves orthogonally polarized to the previous direction. Hence the design presents a dual

In this article, we propose a model to obtain negative electrical permittivity in metamaterials using a conductor wire of rectangular cross-sectional geometry. Plasma frequency in the GHz range is determined in terms of the wire geometry. This new composite dielectric, which has the property of negative electrical permittivity below the plasma frequency, opens new possibilities for GHz devices. Finally

This paper presents an investigation on innovative bandpass negative group delay (NGD) control. The bandpass NGD theory is elaborated with patch antenna-based circuit input impedance. The S-matrix and group delay (GD) models are expressed in function of the circuit geometrical parameters. To validate the no-contact electromagnetic coupling bandpass NGD control, proof of concept is designed, fabricated

Magnetic-free broadband circulator structure based on three switched reflection type delay lines with a total electrical length of 180-degree at the switching frequency is investigated. The nonreciprocal transmission property is modeled and simulated, the impedance mismatching property and reconfigurable direction are studied. A prototype magnetic-free circulator circuit is designed and fabricated

Conformal techniques, based on the covariance of Maxwell's electrodynamics under the full conformal group in four spacetime dimensions, are discussed in relation with the constant input impedance properties of frequency-independent antennas. In particular, we show that by applying suitable conformal transformations to existing self-complementary planar structures like logarithmic spirals, the constant