The dc response of one-dimensional (1D) arrays of superconductor/insulator/superconductor (SIS) junctions under radio-frequency (RF) irradiation has been experimentally studied. The zero-bias resistance as a function of RF amplitude in the low-frequency regime shows an oscillatory behaviour, and can be explained using the phase fluctuation model for Cooper-pair tunnelling. It follows that an effective classical detector theory is applicable and the oscillation period can be compared with the superconducting gap. The results suggest a primary and direct RF detection scheme using 1D SIS junction arrays.
