STC-N12-15-S1-C is a V-Band down-converter that converts millimeterwave signals from a frequency range of 45 to 80 GHz to an output of 10 MHz to 20 GHz. It is compatible with modern Spectrum Analyzers that support external mixers such as Anritsu, Keysight, and Rohde & Schwarz. The down-converter requires 11.25 to 20 GHz at +0 dBm input power as its LO, which can be obtained from a standard 20 GHz synthesizer such as Eravant models STL-SG-022403-S1 or SOT-02220313200-SF-B6. The down-converter has low harmonic, low spurious levels and excellent gain flatness, making it a good candidate to extend low frequency test equipment for millimeterwave testing purposes.