Theoretical increase in radiation efficiency of a small dipole antenna made with a high temperature superconductor

An electrically small wire dipole antenna with a shunted stub matching network has been analyzed to determine the improvement in radiation efficiency that can be achieved by making the metallic components from high-temperature superconducting (high T_c or HTS) material. The analysis shows that significantly higher radiation efficiencies can be obtained with HTS material only if the dielectric losses are kept to very low values. A loss tangent of less than 10^-4 is necessary for any dielectric materials in the transmission lines and support structures for the antenna; a loss tangent of at least 10^-5 is desirable, particularly if the dipole length is 0.1 wavelength or less