Study on SIS Mixers for "ALMA" Band-10

This paper studies superconductor insulator superconductor (SIS) mixers for ALMA Band-10 project. The possible scheme of the ALMA Band-10 cartridge with balanced lens-antenna mixers is presented. The new balanced full-height waveguide SIS mixer comprises two equal mixer chips fabricated on quartz substrates. Each chip contains an RF circuit with hybrid twin-SIS junction NbTiN/Nb-AlO
_x
-Nb/Al. The preliminary experimental study of Band-10 receiver with a double-slot antenna SIS mixer mounted with a 10-mm immersion silicon lens is done to define an optimum layout of the tuning circuit and a combination of materials leading to the best performance of the SIS mixer.