Power and energy in small biconical transmitting antennas

We have obtained a general numerical solution for power and energy in small biconical antennas. The unique shape of biconical radiators makes possible an exact radiation solution; the solution includes the full infinite set of modes and adds to the general knowledge of radiative processes in antennas large or small. Although for this case the power and energy equations are electromagnetically complete, they are in the form of infinite sums over special spherical functions. We have overcome the practical difficulty of their evaluation and we give a detailed description of the real power, reactive power, reactive energy density, and radiation Q for biconical radiators. The real power radiated is independent of the radius. For short antennas, the reactive power is capacitive. The reactive energy per unit length is inductive at the terminal and capacitive elsewhere. The surface Q, Q/sub s/, is calculated versus antenna size for biconical antennas with two different cone angles: 1/spl deg/ and (90-)/spl deg/. These analytically exact power and energy results may be extrapolated to antennas of other shapes for which an exact solutions are not available.