Grating-based Dipole Antenna Configuration for High Gain Directional Radiation characteristics

C K Aanandan,K Vasudevan,M P Jayakrishnan,P Mohanan,V P Sarin

doi:10.7716/aem.v6i1.459

Abstract

The experimental and simulation studies of the radiation performance enhancement of a dipole antenna using metal strip grating are presented in this paper. The subwavelength imaging configuration of the metal strip grating is utilized for enhancing the radiation performance of a dipole antenna working in the S-band. The resultant design shows a gain of 9 dBi and front to back ratio of the design is found to be -23 dB at resonance. The coupling between electric and magnetic resonances provides the necessary impedance matching performance when the antenna is brought in the vicinity of the grating.

Highlights

Electromagnetic wave propagation through periodic structures is well known to the research community over the last century [1]
A periodic arrangement of metallic strips has been used for achieving variable permittivity values and constitutes a well-known category named as artificial dielectrics
The first category constitutes the phase delay type artificial dielectric in which the polarization of the incident field is lying perpendicular to the strip axis

Summary

Introduction

Electromagnetic wave propagation through periodic structures is well known to the research community over the last century [1]. The first category constitutes the phase delay type artificial dielectric in which the polarization of the incident field is lying perpendicular to the strip axis. A negative permittivity material can be represented in the transmission line model by a shunt inductance This property can be used to match an electrically small electric dipole in order to increase the radiated power [8,9]. Eleftheriades used subwavelength grating structures in order to convert evanescent waves in the near field to far field propagating waves [17] He achieved enhanced radiation performance from point source arrays from a metallic grating structure [18]. We are proposing the near field imaging configuration used by Tretyakov [19] for enhancing the radiation performance of a half wavelength dipole antenna. Computational analysis based on the Finite Difference Time Domain (FDTD) technique has been performed on the antenna structure to fully understand the resonant mechanism

Antenna Geometry

Results and discussions

Conclusions