on Space Terahertz Technology WE 1-4 Sideband-separating heterodyne mixer for band 9 of ALMA

In this paper we will present the realization of a side-band-separating (2SB) heterodyne mixer for the frequency range from 602 to 720 GHz. This frequency range corresponds to band 9 band of ALMA. The mixer, in brief, consists of a quadrature hybrid, two LO injectors, two SIS junctions, and three dumping loads. All the parts were modeled and optimized prior construction. The fabricated SSB mixer exploits waveguide technology and has been constructed in the split-block technique. We used state-of-the-art CNC micromachining which permitted to obtain details as small as 70 pm with tolerances of 2 pm. Finally, we will present the performance of the SIS junctions that will be used in the 25B mixer.