Bias System for Sub-mm Receivers
In order to supply clean electrical bias to the cryogenically cooled superconducting sub-mm mixer components a special modular design has been developed at MPI, which is used throughout all of the coherent receivers designed and operated by the group.
The fundamental part of the design is a microcontroller based mainboard which is responsible for biasing and monitoring a chain of components belonging to a single junction:
•The junction itself
•(optional) Coil for magnetic field to suppress the Josephson oscillations in the junction
•(optional) Heater for heating out a junction to eliminate trapped charges
•Cold IF amplifier (HEMT or MMIC)
The mainboards can be hardware and software wise configured for different bias components and ranges and communicate over a high level UDP based communication protocol with superior control unit (receiver control PC). The boards can be aggregated according to the number of junctions used.