Critical currents in a high-T/sub c/ 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.>