SIW CAVITY BACKED'KOCH FRACTAL ANTENNAS AND ARRAYS

Abstract

SIW technology is utilized to synthesize rectangular waveguide in planar form which offers advantages of being easy to integrate with conventional printed planar circuits like microstrip lines and coplanar waveguide. SIW components preserve advantages of both printed planar circuits and rectangular waveguide. They are compact, light, easy to fabricate, flexible, and cost effective; yet have more shielding, low loss, high quality-factor and high power-handling capability. In fast growing commercial and military needs, fractal geometries are used for mobile, miniaturized, and multi-band communication systems. This dissertation presents design method of low profile SIW cavity backed Koch fractal slot antenna and array antenna of the same. The whole antenna including backed cavity and feeding element is completely constructed at a single substrate by using substrate integrated waveguide technique and grounded coplanar waveguide. The analysis tool used to simulate the fields, which are otherwise difficult to analyse, is high frequency structure simulation (HFSS v13) based on finite element method. A rectangular cavity inside the dielectric is designed using SIW technology and CPW feed is used to excite it. On the other side, Koch fractal slots are etched out to radiate the EM wave. Further, linear array of Koch fractal slots is also designed for more directive radiation pattern. On the whole, the designed antenna keeps good radiation performance of conventional cavity backed antenna and has advantages of conventional planar antenna including low profile, light weight, easy fabrication with low cost and convenient integration with planar circuit