Two types of miniaturized cooling systems for High-Temperature Superconduct
ing (HTS) antennas were designed and built, In this paper, details of these
systems, measured and simulated properties of patch antennas installed in
these systems, and results of a seal-off trial for 1 month are reported, Bo
th the systems had portable size and weight and could cool the HTS devices.
When a patch antenna with resonant frequency of 4.9 GHz was installed in t
he Ist cooling system, the radiation pattern of the antenna was strongly fo
cused in the forward direction. This is because the vacuum chamber in which
the antenna was packaged influenced the microwaves radiated from the anten
na. Due to this effect, the directive gain of the antenna was enhanced by 1
1.2 dB. In the 2nd system, a seal-off-trial was carried out to investigate
the airtight property that is necessary for thermal isolation. The temperat
ure of the sample stage could be kept under the critical temperature of YBC
O for 1 month without continuous vacuum pumping. The cooling systems develo
ped in this work are expected to promote the practical use of HTS antennas.