Critical currents in a high-Tc superconducting short dipole antenna

Measurements on a liquid-nitrogen-cooled, superconducting, short-dipole aerial at 550 MHz are presented. The measured relative field strength as a function of frequency is shown for an excitation current well below the critical value. The field strength is shown as a function of frequency for input powers of 25 dBm, 28 dBm, and 31 dBm. An estimate of the RF critical current is made from deviations in linearity with input power. (I.E.)