Harmonic suppression using optimised hexagonal defected ground structure by genetic algorithm

Abstract

This study analyses the effects caused by a new hexagonal defect ground‐plane (DGS) structure when it is applied to a rectangular microstrip antenna and studies its effectiveness to suppress higher‐order modes. To improve the rejection characteristics of the analysed DGS, a genetic algorithm was used to optimise its parameters. Controlling higher‐order modes of the fundamental operating frequency was successfully demonstrated, and the experimental results showed that optimising the hexagonal DGS could enhance the S11 parameter of the fundamental mode while simultaneously suppressing or further attenuating higher‐order modes. Such results are particularly important once DGS is applied for self‐immunity of antennas against harmonic radiations by avoiding the use of a filter circuit.

Improving the Performances of Microstrip Antenna Array using Defected Ground Structure

“…The reflection co efficient has been improved by cascading the defects on the ground plane. Shape of the DGS cells, distance between two units and the placing of the units are the main phenomena which are rigorously studied to improve the radiation performance of the array [11][12][13].…”

“…Article [11] has presented a Novel Stacked Patch Array Antenna with DGS for S band and C band applications. A compact multiband MIMO antenna design has been approached in [12] with high isolation using DGS for C and X band applications. [13] has proposed an antenna array with DGS to reduce mutual coupling (MC) between elements .…”

Broadband circular polarized patch antenna with harmonic suppression

“…To suppress the second and third harmonics a spurline filter was inserted in the antenna microstrip feed line (4) . Defected ground structures (DGS) was used in patch antenna to suppress higher order harmonics (5)(6)(7)(8) .…”

“…The antenna structures in (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) , with higher order mode suppression. However, these antennas have very low bandwidth; some antenna cannot be circular polarized.…”

Grating Lobes Suppression in Frequency Selective Surfaces Using Electromagnetic Band Gap with Square Holes

“…Several techniques have been used to suppress spurious modes, such as the use of defects in the ground plane (Defected ground structure -DGS) of planar antennas [7], [8], or the use of metamaterials in microstrip filters [9], [10] and the use of electromagnetic bandgap (EBG) in planar antennas [11], [12]. However, it is not known to the authors the use of these techniques for suppression or reduction grating lobes in FSS.…”