Printed plane-filling fractal antennas for UHF band

The printed Hilbert antenna has been used for UHF band since it is small, easy to fabricate and impedance-match to common types of planar transmission lines (X. Chen et al, IEEE Soc. Int. Conf. on Antennas and Propag., vol. 2, pp. 581-584, 2003). In this research we studied printed plane-filling antennas of different shapes, including Hilbert, Moore, Peano, Wunderlich 1, 2 and 3 curves. The input impedance and current distribution are calculated through method of moments (MoM) with mixed-potential integral equations (MPIE) formulation. The resonant frequencies are obtained by searching for the roots of the imaginary part of the input impedance. The dependence of the resonant frequency on the shape and size of the antennas are studied, and the current distributions along the antennas at resonant frequency are compared.