In this paper, a planar microstrip sensor based on band-stop filter for determining relative permittivity of solid materials is presented. The proposed has been composed the structure meandered line with T-shaped resonator and an interdigital that connected ground by via. Interaction between caused to increase electric field intensity high sensitivity resolution. microwave using single layer technology fabricated substrate RO4003. samples FR4 RO4350 in double forms as multilayer are placed...

The design of an antipodal Vivaldi antenna for ultra wideband (UWB) applications is presented. main purpose this the reduction three parameters transient distortion, reflection coefficient and cross polarization level. Multi-objective particle swarm optimization (MOPSO) applied to handle these objectives simultaneously. All simulations are performed using CST MWS software. Several cases resultant Pareto fronts compared, finally, a sample front fabricated. To assess time domain performance...

The major deficiency of conventional ‘balanced antipodal Vivaldi antenna’ (BAVA) is its tilted beam over upper working frequencies. This study reports on a new BAVA to overcome this defect. By applying dielectric lens in front the antenna's aperture, beam‐tilting E ‐plane was improved within ultra‐wideband frequency range, as well higher In BAVA, authors have also achieved an acceptable cross‐polarisation. Measurements show that antenna has better than 10 dB return loss aforesaid range....

Using dispersive finite-difference time-domain (D-FDTD) simulations, we show that a pair of gold nanodisks stacked in 'sandwich'-like (end-fire) configuration produces large enhancement the magnetic field when irradiated with plane optical wave, if distance between is optically small. The effect, which can be rationalized terms dipole resonance, due excitation hybridized asymmetric plasmon mode, induced electrical dipoles two disks oscillate out-of-phase. strong response, together simple...

A method to obtain optimum tradeoffs (Pareto front) between sidelobe level (SLL) and beamwidth (BW) in time domain for ultrawideband (UWB) antenna arrays is presented. Multiobjective particle swarm optimization (MOPSO) used deal with these two conflicting objectives. In the process, mutual coupling effects elements are not considered. However, multiple solutions obtained from MOPSO enable designer consider effect as an additional constraint. Each element of array antipodal Vivaldi antenna....

A nanoplasmonic optical filtering technique based on a complementary split-ring resonator structure is proposed. The basic and modal properties of the square-nanoring are studied using group theory. Degeneracy non-degeneracy possible TM odd- even-modes characterized symmetry elements ring structure. Distinctively, proposed allows selecting exciting proper plasmonic modes nanoring in side-coupled arrangement. It found that non-integer can be excited due to presence metallic nano-wall. These...

In this paper, a simple, fast, and novel method for designing tunable terahertz absorber with arbitrary central frequency desired fractional bandwidth is presented. The proposed consists of single layer periodic array graphene ribbons (PAGRs), placed quarter wavelength from metallic ground, separated by dielectric material. An analytical circuit model the used to obtain expressions input impedance device. Then, simple expression determining value capacitance resonance conditions RLC achieve...

A number of recent studies have shown that hybridized antiphase dipolar plasmons, qualitatively similar to magnetic dipole resonances, can be excited in metal-dielectric-metal structures over a wide frequency range. Here, we study how structural asymmetry plasmonic nanosandwiches, composed two Au disks separated by thin SiO2 layer, affects their near- and far-field optical properties using point-dipole analysis, electrodynamics simulations, spectroscopy. We find the strength resonant mode...

A new configuration of the dual-band and dual-polarized antenna is presented, which fed by aperture coupling for existing mobile communication systems working over 870-960 MHz (GSM) 1710-2180 (DCS/UMTS) frequency band. XX-Polar stands an with dual linear slant polarization. In this paper DU band DCS/UMTS Measurement results show that proposed yields good broadside radiation characteristics including symmetric patterns, low cross-polarization level ( <; -14 dB), backlobe (F/B >; 20 dB) high...

A class of nano-scale wavelength-selective optical filters is proposed where the core a metal-insulator-metal square ring replaced with split-ring (SRC). The resonator supports split-ring-resonator-like (SRR-like) resonant modes that are characteristics structure. These highly adjustable, via gap size core, over range hundreds nanometers. can also incorporate tunable materials localized in SRC or placed throughout resonating path. By varying refractive index (1 to 2) material SRC, first and...

In this paper, we numerically study both band-pass and band-stop plasmonic filters based on Metal-Insulator-Metal (MIM) waveguides circular ring resonators. The filter consists of two MIM coupled to each other by a resonator. is made up an waveguide laterally propagating modes Surface Plasmon Polaritons (SPPs) are studied in these structures. By substituting portion the core with air, while outer dimensions resonator kept constant, illustrate possibility red-shift resonant wavelengths order...

We report a numerical study on the optical tuning of notch filter comprised an array engineered graphene microribbons. The normal incidence transmission spectra is created due to light–plasmon coupling in graphene. Besides investigating effect structural parameters and electrostatic gating plasmon excitation, we particularly examine modulation with incident light intensity based significant Kerr Our simulation finite difference time domain method reveals that considerable variation up 12.15...

We study the propagation characteristics of surface Plasmon polaritons (SPPs) on a patterned graphene sheet incorporating subwavelength ribbon resonator and Kerr nonlinear bounding medium (substrate or top cladding) which provides tunable bandpass filtering in THz regime. theoretically via modeling tunability maxima transmission spectrum, corresponding to resonant frequencies resonator, by tuning Fermi level (via an applied gate voltage) altering intensity incident wave. determine...

By exploiting the interesting trait of graphene to have electrically tunable first- and third-order conductivities besides its capability support plasmonic resonances at terahertz frequencies, here, through nonlinear finite-difference time-domain numerical technique we developed, demonstrate a noticeable improvement in conversion efficiency third-harmonic generation (THG) from microribbon array by more than five orders magnitude compared an infinite sheet, under normal illumination waves. As...