Circularly polarized 20-GHz high-temperature superconducting microstrip antenna array

A four-element array of circularly polarized 20-GHz YBa2Cu3Ox microstrip an tennas has been fabricated on LaAlO3 and characterized. The array produced good circular polarization, and the gain of the array at 77 K, relative to a copper array of the same design at 77 K, was approximately 0.75 and 1.3 d B for the two gain measurement methods presented. The relative gain increas ed to approximately 2.2 dB at 30 K, The results demonstrate that high-tempe rature superconductors, when used in microstrip antenna arrays, improve the efficiency of the array, and that circularly polarized microstrip arrays c an be fabricated on LaAlO3.