Characterization of Superconducting Patch Antenna Fabricated by Both-Side Superconducting Thin Film

We have fabricated a patch antenna with a both-side superconducting thin film. The fabricated antenna shows 1dB and 4dB higher gain than that of a single-side superconducting antenna and a normal conducting antenna, respectively. We observed a change of the input impedance characteristics near the T c in the both-side superconducting antenna. This is caused by the temperature dependence of the surface impedance of the superconducting thin film. The gain of this antenna does not change by applying power less than 25dBm below 80K.