Twin slot antenna patterns of a quasi-optical HEB mixer at THz frequencies

Results of far-field beam pattern measurements of the 1.25 THz superconducting Hot Electron Bolometer (HEB) mixer on a quasi-optical integrated lens antenna are presented. The integrated antenna consists of a planar twin slot antenna mounted on the flat surface of an extended hemispherical lens. The beam patterns have been measured at three frequencies: 1.35 THz, 1.395 THz and 1.47 THz with a new setup which has a focus lens between source and HEB mixer. The first order side lobe level equals -13 dB. The dynamic range is nearly 30 dB. The simulated result is also presented, it agrees with measured one well.