Microwave detector response of the Josephson junction arrays

Microwave detector response ( eta ) for three types of superconducting structures-single edge-type Josephson junctions, arrays of series-connected junctions, and arrays of RF-series and DC parallel-connected junctions-were investigated in the frequency range 35-120 GHz. Experimental dependence of eta versus biasing voltage is mainly determined by the interaction of junctions in the array. The selective response, which means a narrow linewidth of Josephson radiation, is observed for the third type of superconducting structure in a small magnetic field changing the phase shift between closely-spaced junctions. These arrays have the advantage in coupling with the external microwave system.