We report on the design and development of a heterodyne receiver, designed to cover the
frequency range 176-256 GHz. This receiver incorporates a niobium superconductor-
insulator-superconductor (SIS) tunnel junction mixer, which, chiefly for reasons of reliability
and ease of operation, is a fixed-tuned waveguide design. On-chip tuning is provided to
resonate out the junction's geometric capacitance and produce a good match to the
waveguide circuit. Laboratory measurements on the first test receiver indicate that the …

We report on the design and development of a heterodyne receiver, designed to cover the
frequency range 176 GHz to 256 GHZ. This receiver incorporates a niobium
superconductorinsulator-superconductor (SIS) tunnel junction mixer, which, chiefly for
reasons of reliability and ease of operation, is a fixed-tuned waveguide design. On-chip
tuning is provided to resonate out the junction's parasitic capacitance and produce a good
match to the waveguide circuit. Laboratory measurements on the first test receiver indicate …