Abstract: A novel method is proposed for analyzing the sleeve monopole at the center of a circular ground plane. Using the moderately thick cylindrical model and sinusoidal interpolation basis function, the sleeve monopole at the circular ground plane is analyzed by the moment method. The input impedance and radiation pattern are given. Finally, a practical sleeve antenna, with the VSWR less than 3.0 in 225~515MHz frequency band, is designed according to the analysis above. he results show that the model used in this paper is more accurate and practical.

Key words: sleeve monopole antennas, circular groud plane, method of moment, sinusoidal interpolate basis