A 220 GHz low noise superconducting receiver with wide instantaneous operating bandwidth

A 220 GHz mixer chip based on a 3-junction series distributed superconducting mixer has been developed. This mixer employs a design, which minimizes the output capacitances, such that it can offer a wide instantaneous bandwidth of up to 12 GHz. We have incorporated this mixer into a receiver package and a dedicated automatic test bench has been developed to characterize its performance. The receiver demonstrates ultra low noise temperature, as low as 32 K, or 3 hν/k. The measured noise temperature remains below 50 K beyond 10 GHz IF.