Printed fractal antennas

One aspect of this paper is to describe the possibilities for reducing the overall size of a monopole so that they can be hidden within a system rather than protrude from it. Improved bandwidth results from the bow-tie monopole but there are instances where individual bands rather than a single band is preferable, for example for rejection of unwanted signals. One class of antenna to replace the monopole is the printed fractal antenna. Two types of fractal antennas are discussed, the Koch fractal patterns and the Sierpinski gasket which is akin to a printed bow-tie antenna. In both classes of antenna their radiation patterns, efficiency and frequency response as well as dimensions are discussed and compared. The principal application for the work described here is to provide hidden antennas on vehicles for multiband radio and television services. These include AM, FM and DAB services.