Superconducting antennas

The applicability of superconductors to antennas is examined with emphasis on the roles of external and internal fields. Six potential implementations have resulted. These are superdirective arrays, millimeter-wavelength arrays, electrically small antennas, matching of antennas, phasers for electronic scanning, and traveling-wave array feeds. Most superdirective arrays are still impractical, because of high Q and strict tolerances. Large millimeter arrays appear feasible, due to a major reduction in feed losses. For electrically small antennas, high Q again limits applicability. However, matching of small superdirective arrays and all electrically small antennas, including large transmit antennas, is very attractive, as matching network losses are greatly reduced. Switched-line phasers offer a major size reduction; phase control by means of temperature of a single line poses some problems. Traveling-wave array beam steering by means of temperature also appears possible. The last two utilize the kinetic inductance provided by thin films