ИСТИНА

Matching issues of active electrically small antenna based on superconducting quantum array are analyzed and discussed. To keep the highly linear antenna characteristics, the active antenna ought to be loaded with much higher impedance than the normal resistance of the superconducting quantum array. At the same time, the interface in use is to be well matched with the following antenna receiver device such as superconductor Analog-to-Digital Converter characterized by low input impedance of about normal resistance of overdamped Josephson junction. To provide optimal matching between the active antenna and the low-impedance device, a broadband filter realizing impedance transformation from 50 Ohm to 5 Ohm is developed.