Performance of a 1.3-THz twin-slot antenna superconducting HEB mixer integrated with different elliptical lenses

The performance of a 1.3 THz twin-slot antenna coupled superconducting hot-electron-bolometer (HEB) mixer integrated with elliptical lenses of different extension lengths are investigated. The elliptical lenses have the same radius but different extension lengths: 1.109 mm, 1.149 mm, 1.189 mm and 1.229 mm. The measured noise temperature and frequency response appears insensitive to the lens extension length. The far-field beam-patterns, directivity and Gaussicity are clearly related to the lens extension length.