Abstract: A method for analyzing wideband antennas is introduced.Characteristic modes and singular value decomposition are used at a small number of frequencies, and a set of frequency independent basis functions is constructed over the entire frequency range.The antenna characteristics can be determined rapidly by the frequency independent basis functions.A bowtie antenna and a slotted antenna are analyzed using the proposed method.The results agree with those obtained by direct method of moments, indicating correctness and effectiveness of the method.

Key words: characteristic modes, basis functions, reduced order subspace, method of moments, wideband antenna, singular value decomposition