Multiband fractal square Koch antenna design for UHF/SHF application

Abstract

There exists various types of antennas for various purposes, but the interest in this area is increasing day by day. There have been ever growing demands for antenna designs that possess the highly desirable properties: compact size, low profile, multi-band, wide bandwidth, high gain, improved SWR etc. Fractal antennas can be used to meet these demands. This paper represents the analysis and design of multiband square Koch fractal dipole antenna, where it is shown that as the iterations are increased, the band of frequencies also increase. The designed antenna has operating frequencies for first iteration are of 496 MHz and 1430 MHz, and for second iteration are of 460 MHz, 1248 MHz, 1926 MHz and 4390 MHz with acceptable bandwidth, which has useful applications in UHF/SHF. The radiation characteristics, SWR, reflection-coefficient, input impedance and gain of the proposed antenna are described with 4NEC2 Software package. Here, the antenna is placed in the XY-plane for the first iteration and in YZ-plane for the second iteration.