Showing papers in "Electromagnetics in 2018"
TL;DR: In this article, a two-segment rectangular dielectric resonator antenna is designed for ultra-wide application, which exhibits a maximum gain of 7.2 dBi at 10 GHz along with 95% of peak efficiency at 3 GHz.
Abstract: In this paper, a novel two-segment rectangular dielectric resonator antenna is designed for ultra-wide application. These dielectric resonator antennas, having different dielectric material, are placed side by side and are excited with common micro-strip feed. Further, the effect of defected ground is also investigated. The proposed structure offers a wide bandwidth of 131.24% for |S11| < –10 dB from 2.8–13.49 GHz catering needs of many wireless applications for S-band, C-band, X-band, WLAN, and WiMAX. The proposed antenna is fabricated and tested to validate the simulated results. This antenna exhibits a maximum gain of 7.2 dBi at 10 GHz along with 95% of peak efficiency at 3 GHz.
16 citations
TL;DR: In this article, a new power divider is designed initially; then, a new PD has been proposed by replacing the conventional transmission lines with rectangular-shaped and radial-shaped resonators.
Abstract: In this paper, a new power divider (PD) is designed initially; then a new PD has been proposed by replacing the conventional transmission lines with rectangular-shaped and radial-shaped resonators....
15 citations
TL;DR: In this article, a hybrid method for computing electromagnetic scattering from target above composite rough surface of ground and near sea in adjacent region is proposed, where first, a kind of composite rough su...
Abstract: This paper proposes a hybrid method for computing electromagnetic scattering from target above composite rough surface of ground and near sea in adjacent region. First, a kind of composite rough su...
12 citations
TL;DR: In this article, a novel arrangement of elliptical nanoantenna has been noticed for improving the electric field and energy enhancement in hot spots for mid-infrared range, where elliptical cylinders and elliptical rings are developed for dark mode by the concentration of plasmonic charges in a limited area, and the interaction between bright and dark mode has been used for the Fano shape of the extinction cross section.
Abstract: Fano resonance has been considered especially in nanostructures for energy enhancement and creating hot spots in nanoparticles based on plasmonic properties. In this paper, a novel arrangement of elliptical nanoantenna has been noticed for improving the electric field and energy enhancement in hot spots for mid-infrared range. For this, elliptical cylinders and elliptical rings are developed for dark mode by the concentration of plasmonic charges in a limited area, and the interaction between bright and dark mode has been used for the Fano shape of the extinction cross section. The combination of dipole arrangement has been implemented based on elliptical hollow cylindrical particles with various inner radios for arousing the Fano resonance. Finally, π- and T-shaped models are studied for Fano resonance, and the electric fields are compared in all cases. Exactly, this study is important for two main reasons: (1) it shows how we can control the extinction cross section and (2) it shows that by dist...
11 citations
TL;DR: In this article, a compact and sharp-rejection ultra-wideband (UWB) microstrip bandpass filter (BPF) is presented, which is constructed with multiplemode resonator (MMR) and split ring resonator(SRR).
Abstract: A compact and sharp-rejection ultra-wideband (UWB) microstrip bandpass filter (BPF) is presented. The proposed filter is constructed with multiple-mode resonator (MMR) and split ring resonator (SRR...
11 citations
TL;DR: In this paper, an inverted pyramid-shaped Sierpinski fractal Dielectric Resonator Antenna (DRA) is designed and investigated, and the geometry is a Sierspinski Gasket with rectangle as a base element.
Abstract: In this paper, an inverted pyramid-shaped Sierpinski fractal Dielectric Resonator Antenna (DRA) is designed and investigated. The geometry is a Sierpinski Gasket with rectangle as a base element. P...
10 citations
TL;DR: The fabricated antenna is useful in impulse GPRs for humanitarian demining due to its high penetration depth, wide bandwidth, relatively small dimensions, and low axial ratio.
Abstract: A low cost cavity-backed logarithmic spiral antenna with a very wideband balun is presented for detection of Anti-Personnel land mines in ground penetrating radars. It covers a wide frequency range...
9 citations
TL;DR: In this article, a novel design of circularly polarized gap-coupled wideband antenna with defected ground structure is presented, which consists of gap-Coupled C-shaped radiators.
Abstract: In this paper, a novel design of circularly polarized gap-coupled wideband microstrip antenna with defected ground structure is presented. This antenna consists of gap-coupled C-shaped radiators an...
8 citations
TL;DR: In this paper, a modified hexagonal slot antenna for wideband applications is proposed, which allows the antenna to operate within the frequency range of 2.16-3.42 GHz with the fractional bandwidth of 45.16%.
Abstract: This paper explains the design and analysis of modified hexagonal slot antenna for wideband applications. The proposed antenna is fabricated on FR-4 substrate. On one side of square substrate, a square patch is printed and one hexagonal slot and six circular slots are etched. On the other side of the substrate, a rectangular microstrip line is printed to feed the antenna. High-frequency structure simulation (HFSS) software is utilized to optimize the different antenna parameters. The simulated and measured results are compared, and these are in good agreement. The proposed design and feeding technique allows the antenna to operate within the frequency range of 2.16–3.42 GHz with the fractional bandwidth of 45.16%. The broadsided gain of proposed radiator is more than 2.6 dBi. The proposed antenna is quite appropriate for IMT (2.3–2.4 GHz), Bluetooth (2.4–2.5 GHz), WLAN (2.4–2.484 GHz), and WiMAX (2.5–2.69 GHz) applications.
7 citations
TL;DR: In this article, a new structure for wideband circularly polarized (CP) slot antenna is proposed, which consists of a circular patch with two rectangular slots, which are parallel to CPW feed line, excites two resonance modes for wide-band performance.
Abstract: A new structure for wideband circularly polarized (CP) slot antenna is proposed in this article. The designed antenna consists of a circular patch with two rectangular slots, which are parallel to CPW feed line, excites two resonance modes for wideband performance. To achieve CP operation, an inclined coupling slot loaded feed line on the ground is used. Furthermore, the proposed antenna is an enhanced version of earlier wideband CP antennas having a compact structure with a low-profile of 0.023λo (λo stands for the free space wavelength at 4.46 GHz) and ground size of 30 mm × 30 mm. It operates over the impedance bandwidth of 88.9% (relative to the center frequency of 4.5 GHz) and 3-dB axial ratio bandwidth found for this band is 2.7% (relative to the center frequency of 4.46 GHz). To verify the performance of the designed antenna, the experimental results match well with the simulated results.
7 citations
TL;DR: In this paper, a compact bandpass filter (BPF) using half-mode substrate integrated waveguide technology is presented, where the source-load cross-coupling structure has been used in the BPF and the transmissibility has been evaluated.
Abstract: This article presents a compact bandpass filter (BPF) using half-mode substrate integrated waveguide technology. The source-load cross-coupling structure has been used in the BPF and the transmissi...
TL;DR: In this paper, a novel diplexer operated at 1.8 GHz and 2.4 GHz is proposed, which is based on the coupled microstrip line and features low insertion loss, high isolation, simple topology, and compact size.
Abstract: A novel diplexer operated at 1.8 GHz and 2.4 GHz is proposed. It is based on the coupled microstrip line and features low insertion loss, high isolation, simple topology, and compact size. As compa...
TL;DR: A MLP-based neural model for an efficient 1D DoA estimation of highly correlated stochastic EM sources is proposed and algorithm for optimal selection of correlation matrix elements from the upper triangle of the matrix is suggested to reduce the number of antenna array elements needed to obtain an accurate neural model with relatively simple architecture.
Abstract: MultiLayer perceptron (MLP)-based neural model for an efficient 1D DoA estimation of highly correlated stochastic EM sources is proposed. Model extracts this information from a spatial correlation matrix obtained by sampling stochastic signals by a receiving antenna array. Algorithm for optimal selection of correlation matrix elements from the upper triangle of the matrix is suggested to reduce the number of antenna array elements needed to obtain an accurate neural model with relatively simple architecture. This approach is verified by determining the azimuth position of two sources with the mutual correlation in the range [0.8–0.95] using antenna arrays with different number of elements.
TL;DR: In this paper, an axially symmetric diffraction antenna of a new type is presented and studied in details in the paper "An Axially Symmetric Diffraction antenna based on the effect of Cherenkov-like radiation".
Abstract: An axially symmetric diffraction antenna of a new type is presented and studied in details in the paper. The antenna is based on the effect of Cherenkov-like radiation. In contrast to diffraction a...
TL;DR: In this paper, a hexagonal defected ground structure-integrated rectangular microstrip antennas were used to investigate the input and radiation characteristics of a patch to the present authors, and the experimental results showed that the bandwidth and gain properties of such antenna can also be improved by judicious exploitation of the defect geometry on ground plane.
Abstract: The experimental investigations with hexagonal defected ground structure-integrated rectangular microstrip antennas show some interesting results on the input and radiation characteristics of a patch to the present authors. Unlike the earlier reports on implementation of defected ground structure in microstrip antenna for lowering only cross-polarized radiation, the present investigation shows that the bandwidth and the gain properties of such antenna can also be improved by judicious exploitation of the defect geometry on ground plane. Around 58% input impedance bandwidth (covering the whole Ku band) with high gain (around 9.1–9.4 dBi) and stable radiation pattern is obtained from the present structure.
TL;DR: In this article, a 60 GHz planar Fabry-Perot cavity (FPC) antenna with a circularly polarized (CP) radiation characteristic is proposed as a good candidate for millimeter-wave wireless systems.
Abstract: In this paper, a 60 GHz planar Fabry-Perot cavity (FPC) antenna with a circularly polarized (CP) radiation characteristic is proposed as a good candidate for millimeter-wave wireless systems. A sparse array design is employed to enhance the gain bandwidth (GBW) product of the antenna. Complete formulations for circular polarized radiation are developed to serve as a general guideline scalable to any frequencies. The theoretical results using ideal point sources are validated by numerical analysis using the finite elements method (FEM). In the full-wave simulations, the ideal sources are replaced by four annular-ring slot antennas to excite the FPC.
TL;DR: In this article, the authors deal with a new electromagnetic model in evaluating the radar multipath scattering and its influence on radar High Resolution Range Profile (HRRP) characteristics of a low altitude.
Abstract: The present paper deals with a new electromagnetic model in evaluating the radar multipath scattering and its influence on radar High Resolution Range Profile (HRRP) characteristics of a low altitu...
TL;DR: In this paper, a simple perturbation technique using an off-centered metal cylinder in rectangular waveguide cavity to realize a triple-mode wideband bandpass filter was presented.
Abstract: This paper presents a simple perturbation technique using an off-centered metal cylinder in rectangular waveguide cavity to realize a triple-mode wideband bandpass filter. A TM mode along w...
TL;DR: In this article, a Coplanar-Waveguide-fed tapered ring dual-band antenna with dual band notch characteristics is presented. The proposed antenna comprises of a tapered round radiator and two...
Abstract: A Coplanar-Waveguide-fed tapered ring dual-band antenna with dual band notch characteristics is presented in this article. The proposed antenna comprises of a tapered ring radiator and two ...
TL;DR: In this article, a compact broadband dual-polarized stacked patch antenna with the aperture coupled microstrip feed is proposed, where a parasitic disc patch is added to enlarge the bandwidth.
Abstract: In this paper, a compact broadband dual-polarized stacked patch antenna with the aperture coupled microstrip feed is proposed. By adding a parasitic disc patch, the bandwidth is effectively broaden...
TL;DR: The proposed IEDG-DDM results in an effective nonoverlapping domain decomposition preconditioner and a fast convergence of Krylov sub-space iterative solvers can be achieved.
Abstract: A novel implementation of the integral equation discontinuous Galerkin (IEDG)-based domain decomposition method (DDM), named as the IEDG-DDM, is developed for the efficient analysis of electromagne...
TL;DR: In this article, a cross-coupled corrugated notch Dielectric Resonator Antenna (DRA) is proposed, which is applied on the dielectric resonator.
Abstract: In this paper, a cross-coupled corrugated notch Dielectric Resonator Antenna (DRA) is proposed. The corrugated surface is applied on Dielectric Resonator (DR), which resembles with the feat...
TL;DR: In this article, a two-order branch-line balun topology, featuring enhanced electric performance, is proposed, which is a branch line balun with output isolation and impedance matching.
Abstract: Primary challenges of developing a branch-line balun lie in the output isolation and impedance matching. A two-order branch-line balun topology, featuring enhanced electric performance, is ...
TL;DR: In this article, a reflectarray antenna using sub-wavelength fragmented elements is proposed, where the size of the element is at the working frequency of 5.8 GHz and a full 360° phase range is achieved due to the flexibili...
Abstract: A reflectarray antenna using sub-wavelength fragmented elements is proposed. The size of the element is at the working frequency of 5.8 GHz. A full 360° phase range is achieved due to the flexibili...
TL;DR: In this paper, several miniaturized microstrip fifth-order lowpass filters with structure of unit artificial transmission line are presented, where active elements including inductors and capacitors are constructed by microstrip structures directly by parameter extraction from electromagnetic simulation.
Abstract: In this article, several miniaturized microstrip fifth-order lowpass filters with structure of unit artificial transmission line are presented. Reactive elements including inductors and capacitors are constructed by microstrip structures directly by parameter extraction from electromagnetic simulation. A transmission zero in stopband can be achieved by inductors and capacitors (LC) series-resonant circuit composed by parallel-plated capacitors and connecting lines. Meanwhile, loading interdigital capacitors would bring in another transmission zero. In comparison, fifth-order Butterworth and Chebyshev lowpass filters with one and two transmission zeros are fabricated, respectively, to verify the extra transmission zero effect caused by LC shunt resonant-circuits with interdigital capacitors. The proposed lowpass filters are compact and their sizes occupies less than 40% of conventional microstrip lowpass filters. The simulated and measured results demonstrate good agreements between them, which ver...
TL;DR: In this paper, an analytical model based on the equivalent circuit method is presented to predict the electromagnetic shielding effectiveness (SE) of perforated metallic rectangular enclosure with external waveguide, in which the electrically small aperture is represented by a four-terminal network, and the external wave guide and enclosure are modeled as transmission line.
Abstract: An analytical model based on the equivalent circuit method is presented to predict the electromagnetic shielding effectiveness (SE) of perforated metallic rectangular enclosure with external waveguide. In this model, the electrically small aperture is represented by a four-terminal network, and the external waveguide and enclosure are modeled as transmission line. By this way, the SE of any position of the enclosure under planewave illumination can be calculated fast and accurately over a wide frequency range (0 ~ 3 GHz). Simulation results of the proposed model are in accord with that of the transmission line matrix method, which verifies the accuracy and reliability of the model. The shielding characteristics of the perforated enclosure with external waveguide are also analyzed. The effects of parameters of aperture position, observation point position, and external waveguide length are discussed in detail. Simulation results show that the external waveguide can effectively improve the SE of the...
TL;DR: In this paper, a dual-band rat-race hybrid with phase compensation at microwave frequencies was proposed, and the proposed hybrid has good magnitude and improved phase responses, but the phase compensation was not considered.
Abstract: This paper presents a dual-band rat-race hybrid with phase compensation at microwave frequencies. The proposed rat-race hybrid has good magnitude and improved phase responses. Stub-loaded transmiss...
TL;DR: In this article, a new compact microstrip dual-narrowband bandpass filter with wide and strong rejection level in the first and last stopband is introduced, which is controllable by a resonator without changing the center frequency of the first passband.
Abstract: In this article, a new compact microstrip dual-narrowband bandpass filter is introduced with wide and strong rejection level in the first and last stopband. The location of the second passbands is controllable by a resonator without changing the center frequency of the first passband. The filter structure consists of coupled and stepped transmission lines and radial stubs. Also, fractional 3 dB bandwidth of the first and second passband are 2.35 and 1.62%. The last stopband of the proposed filter is wide. The overall size of the proposed filter is , where is the guided wavelength at the first center frequency.
TL;DR: Non-line of sight (NLOS) radio propagation channel characteristics are presented and a fundamental issue of diffraction loss and shadowing phenomena modeling for urban cellular communication systems in this band is considered.
Abstract: The 0.3–6 GHz band will be a key component of fifth-generation (5G) wireless cellular communication systems. This paper presents non-line of sight (NLOS) radio propagation channel characteristics a...
TL;DR: In this paper, simple closed formulae were derived for the wave number of the TM0 mode guided by a plane conductor coated with a dielectric slab, for the first time.
Abstract: Simple closed formulae are derived for the wave number of the TM0 mode guided by a plane conductor coated with a dielectric slab, for the first time. Finite conductivity and dielectric loss are accounted for. So is the retardation effect of colliding electrons, in order to extend the frequency-range of the proposed formulae beyond 1 THz. Those formulae are applied in two examples.