THz Frequency Up-Conversion using Superconducting Tunnel Junction

In this letter we present the characterization of the first frequency up-converter using distributed superconducting tunnel junctions. The power of the frequency up-converted signal was large enough to pump an SIS mixer. The efficiency of the distributed superconducting tunnel junction is 11-22 % for a fractional bandwidth of 7% with excellent spectral line purity. The -3 dB line width of the up-converter signal is better than 1 Hz, which was the lowest resolution bandwidth of the spectrum analyzer.