A wire model for the Sierpinski gasket type monopole antenna and a truly broadband bent-wire antenna

In recent years fractal concepts have been increasingly used to design multi-band antennas (D.H. Werner and S. Ganguly, IEEE A&P Magazine, vol. 45, pp. 38-57, 2003; S. Best, ibid., vol. 45, pp. 9-28, 2003), because of their so-called self-similar characteristic and space-filling capability, and as a novel antenna miniaturization technique (J.P. Gianvittorio and Y. Rahmat-Sami, ibid., vol. 44, pp. 20-36, 2002). The attention grabbing Sierpinski gasket geometry has been used to design both monopole and patch type antennas, but only the latter is suitable for conformal applications (J. Yeo and R. Mitra, IEE Antennas & Propagation, ICAP 2003, Conf. Publ. No. 491, pp. 143-146, 2003), However the Sierpinski patch gasket antenna may not perform as well as a monopole without modification, because of its fixed height above the ground plane. The purpose of this paper is to analyze by numerical simulation (NEC 4D) a triangular wire antenna that simulates the performance of the Sierpinski gasket antenna, and provides an insight into how this gasket antenna functions as it does. Also, while the Sierpinski gasket geometry is said to exhibit broadband performance, it is not really a broadband antenna. The paper concludes with a mini study of a simple wire antenna that is truly broadband.