A high gain YBCO antenna array with integrated feed and balun

A supergain antenna array of closely spaced printed dipoles made of thick film YBCO was designed and experimentally tested. An optimization of the directive gain with respect to interelement spacing, dipole length, and other circuit parameters, subject to constraints in array size, was performed by combining the spectral domain method of moments and transmission line theory. The design procedure accounts far losses associated with the strip material, both at the feed and the radiating dipoles, and power dissipation in the substrate. A practical design of a sixteen element array is demonstrated, with an integrated feeding network and a balun, also made of high-T/sub c/ superconductors (HTS). Performance is compared against simulated data. The superconducting array has gain significantly higher than that of a similar supercooled silver array albeit at the expense of transmission bandwidth. It is shown that supergain is practically achievable by miniature, printed HTS dipole arrays.<>