A high-density customizable microwave vacuum feedthrough for cryogenic applications

We have designed, constructed, and tested an electrical vacuum feedthrough that can carry a large number of microwave signal lines, has high vacuum compatibility, and is highly customizable. We found that it had a leak rate of approximately 10^-7 Pa L/s (7.5 × 10^-9 torr L/s), making it suitable for high-vacuum systems such as cryostats. The feedthrough is low-cost, and the printed circuit board-based design allows the choice of any surface-mountable microwave connector. We additionally verified operation through consistent use on a real cryogenic system and verified the mechanical robustness of the feedthrough.