The 1221A-54AC from ACST GmbH is a Frequency Multiplier with Input Frequency 13.88 to 20.37 GHz, Output Frequency 750 to 1100 GHz, Input Power 0 to 5 dBm, Output Power -19 to -11 dBm, VSWR 1.80:1. Tags: Waveguide, Waveguide Multiplier. More details for 1221A-54AC can be seen below.