Miniaturization Of Planar Antennas Using Some Fractal Geometry

Abstract

Nowadays, there is a high demand for compact, efficient, multiband, and wideband wireless antennas. The Microstrip patch antenna (MPA) is the best planar antenna to fulfil these demands. MPAs provide more improved performances when various several fractal geometries are applied to them. Thus, the design of such MPAs based on various fractal geometries are the current trend in the field of planar antenna design. newlineIn this dissertation, we have designed and analyzed eight numbers of planar antenna designs for several wireless applications. Six antenna designs out of these designs are based on fractal geometry. Out of eight MPA designs, four designs are presented in chapter 3. Chapter 4 includes one MPA design, and chapter 5 includes 3 MPA designs. The first MPA design is a miniaturized fractal monopole antenna using Sierpinski carpet fractal geometry suitable for Multiband applications. This design uses a square patch of dimension (63×63) mm2. The ground and substrate dimensions are of (70×70) mm2. The FR4 material with a relative permittivity value of and#949;r = 4.4 is considered as the substrate material. This MPA is designed considering up to the third iteration of fractal geometry by using CST MWS software. The third iteration design provides the best results such as antenna size minimization of 52.1 % with a higher return loss of -38.53, VSWR of 1.36, gain of 7.4 dB, directivity of 9.3 dB and a bandwidth improvement of 2.09 %. The second MPA design is a miniaturized fractal monopole antenna that uses Koch curve fractal geometry for multiband applications. This design uses a generation curve that uses a 6 mm dimension of a square microstrip patch. CST MWS software is used for the design and simulation of this antenna. This proposed generation curve is used for the generation of multiple iterations of this design. The 2nd iteration provides comparatively best results like higher return loss of -25.1, VSWR of 1.1, gain of 6.1 dB, directivity of 6.08 dB, and bandwidth improvement of 7.61 %. The third antenna design is a