In this paper,design optimization of Log Periodic Dipole Antenna (LPDA) has been carried out using Genetic Algorithm. The design objectives of this work is maximization of gain and minimization of VSWR.This has been achieved by variations in geometrical parameters of log periodic dipole antenna like maximum length, minimum length,spacing factor (σ). The simulation results have attained gain fro...

We study theoretically the spatial distribution of polarizations in array resonant electromagnetic dipole emitters coupled to a one-dimensional waveguide. The ratchet effect manifests itself asymmetry emitter occupations along under symmetrical pumping from both sides. occupation is driven by periodic modulation time resonance frequencies. find numerically and analytically optimal conditions fo...

When arranged in a periodic geometry, arrays of metallic nanostructures are capable supporting collective modes known as lattice resonances. These modes, which originate from the coherent multiple scattering between elements array, give rise to very strong and spectrally narrow optical responses. Here, we show that, thanks their nature, resonances array nanoparticles can mediate an efficient lo...

In this work, we theoretically study the optical properties of a graphene nanoribbon with quantum dot (QD) on it. The system consists dimensions 400 × 3100 (nm2) and nanoscale radius. is symmetrically located at center to simplify mathematical model. To calculate (susceptibility) system, broadband electromagnetic wave (0.5–2.5 μm) applied structure model dipole-dipole interaction. Considering i...

It is shown that Bound States in the Continuum (BSC) exist an elastic structure consisting of a periodic double array thin (subwavelength) cylindrical scatterers embedded background material, where distance between arrays taken to be large comparison both wavelength and period array. The medium supports waves with all polarizations, one longitudinal two transverse, each which has different phas...

This paper is concerned with the following elliptic system:$$ left{ begin{array}{ll} -triangle u + b(x)nabla u + V(x)u=g(x, v), -triangle v - b(x)nabla v + V(x)v=f(x, u), end{array} right. $$ for $x in {R}^{N}$, where $V $, $b$ and $W$ are 1-periodic in $x$, and $f(x,t)$, $g(x,t)$ are super-quadratic. In this paper, we give a new technique to show the boundedness of Cerami sequences and estab...

Abstract—A bidirectional high gain four-element printed dipole array for WLAN (2.4/5.8GHz) applications is analyzed and successfully implemented in this paper. Each element used is a double-side printed dipole fed with a balance twin-lead transmission line. A wide-band balun is implemented for the dipole array. Both simulated and measured data are pretty matched. According to the measured resul...

This paper presents an optimum design technique of an asymmetric V-dipole antenna and it’s a three-element Yagi-Uda array using Genetic Algorithm (GA). The optimization parameter for the V-dipole is the directivity and that for the Yagi-Uda array are the input impedance and directivity. The theoretical analysis has been done using a Moment-Method technique in a very simple step-by-step way, and...

Log-Periodic Dipole Antenna (LPDA) is a common and important broadband antenna, due to its non-frequency dependent characteristic. However, in the conventional design, the physical size is restricted to the longest oscillator dipole w ith the low est resonant frequency, which is quite large and constrains its application. To realize the antenna miniaturization, many methods, including loading t...