Circularly polarized energy flux densities

As one of the methods to understand electromagnetic wave propagation and radiation mechanism of antennas, it is useful to use streamlines of electromagnetic energy flux densities. However, the Poynting vector, as an electromagnetic energy flux density, does not include any information about polarization. In this paper, the circularly polarized energy flow is explained in light of the circularly polarized electromagnetic energy flux densities proposed recently. As the most fundamental example, fields of circularly polarized cross dipoles are drawn by using the circularly polarized electromagnetic energy flux densities. Then, radiation characteristics of circularly polarized antennas are explained by newly defined circularly polarized radiation efficiency and directivity. Moreover, the conventional delta source excitation model for linear antennas is unable to explain the circularly polarized wave radiation from a conical spiral antenna composed of thin conductor.