The D4I4012YMG from DiTom Microwave is a 2-Port Single/Dual Junction Cryogenic Isolator that operates from 4 to 12 GHz. It provides an isolation of more than 24 dB and has an insertion loss of less than 2 dB. This isolator can handle an average forward power of 20 W, a peak input power of 30 W, and has a return loss of more than 12 dB. It can operate at temperatures below 77 K and is available in a magnetically shielded module that measures 2.00 x 1.03 x 0.56 inches and has SMA male/female connectors.
