STC-20-15-S1 is a V-Band down-converter that converts millimeter-wave signals from a frequency range of 50 to 75 GHz to the baseband at 10 MHz to 1.6 GHz. The down-converter requires 12.5 to 18.75 GHz at minimum +3 dBm input power, which can be obtained from a standard 20 GHz synthesizer, such as Eravant models STL-SG-022203-S1 or SOT-02220313200-SF-B6. The down-converter has low harmonic levels and excellent gain flatness, making it a good candidate to extend low frequency test equipment for millimeter-wave testing purposes.