SIMPLE DERIVATION OF DYADIC GREEN FUNCTIONS OF A SIMPLY MOVING, ISOTROPIC, DIELECTRIC-MAGNETIC MEDIUM

ABSTRACT: A multiband diamond-shaped Sierpinski gasket monopoleantenna is described. The radiation pattern of wideband monopole an-tennas like the circular-disk and diamond monopole antennas degradesas frequency increases. In this paper, several cutouts based on the Sier-pinski gasket geometry are made in the diamond monopole antenna inorder to improve the radiation pattern of the antenna. It is experimen-tally shown that a multiband diamond-shaped Sierpinski gasket mono-pole antenna with a significant improved radiation pattern can beachieved by making cutouts in the diamond monopole antenna. © 2006Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1069–1073,2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21603 Key words: wideband monopole antenna; diamond monopole; radiationpattern; Sierpinski gasket; multiband 1. INTRODUCTION Multiband and wideband monopole antennas have attracted a greatdeal of attention for modern wireless communication systems. Thecircular-disk monopole antenna with a very large impedance band-width was introduced in [1] and further studied in [2]. The patternof the circular-disk monopole antenna degrades as frequency in-creases. The multiple-ring monopole antenna was proposed in [3].It consists of a set of self-similar circular rings, which are super-imposed to form the single antenna unit, as shown in Figure 1. Themultiple-ring monopole antenna is a multiband antenna and due tothe discrete structure of the multiple rings, it shows improvedradiation pattern at higher operating bands in comparison to thecircular disk.In this paper, the diamond monopole antenna is investigatedandseveralcutoutsbasedontheSierpinskigasketgeometry[4]aremade in the antenna in order to improve the radiation pattern athigh frequencies. Two diamond monopole antennas with flare