Hg-based HTS loop antenna used for the demonstration of a passive radiative cooler for spacecraft

The TCSUH developed a passive radiative cooler, which is expected to be used in a spacecraft for the cooling of HTS microwave devices. For the demonstration of the cooler, in this work Hg system and Y-123 HTS materials were used on the fabrication of loop antennas. The matching circuit was designed to let the antennas work at frequencies much lower than the resonant frequencies of the antennas. The measured results showed that as the temperature went down, the efficiencies of Hg and Y-123 loop antennas increased 8dB and 8.5dB around 110K and 85K, respectively, but the increase of the Hg antenna was much slower.