Distributed Josephson junction arrays as local oscillators

The power and linewidth of the radiation, near 250 GHz, of small distributed Josephson junction array sources have been measured using a single-chip integrated source and receiver. The intermediate frequency (IF), coupled off the chip to a room-temperature spectrum analyzer, permitted a direct measurement of the oscillator linewidth. The one-dimensional arrays were of a novel design with junctions placed in 1/4 wavelength lumps separated by one half wavelength. The measured power ( approximately=2 mu W) and linewidth ( approximately=10 MHz) for the 10 junction sources were in reasonable agreement with those obtained from computer simulations.<>