Observation and prediction on the characteristic modes' variation with frequency

An observation and prediction on the characteristic modes' variation with frequency is made in this paper. The closed-forms of the characteristic modes (CMs) of metallic sphere and numerical results of the CMs of metallic rectangular plate are observed. It can be observed that the sphere's distributions of characteristic currents are independent of frequency, and frequency almost does not affect the rectangular plate's distributions of characteristic currents. It can be predicted from the observation that the canonical structures' distributions of characteristic currents are independent of frequency, and frequency almost does not affect the non-canonical structures' distributions of characteristic currents.