A 0.33-0.73 THz source based on phase-locked Josephson flux-flow oscillator

A new implementation for a terahertz flux-flow oscillator (FFO) based on a long Josephson junction is presented. The oscillator is integrated with the lens antenna on a single chip providing the THz emission in the open space, and with a harmonic mixer (HM) based on a SIS junction for a frequency and phase locking. We used the double slot antenna to output the emission from the planar transmission line to the open space, this antenna is coupled to the elliptical silicon lens forming narrow output beam of THz radiation. Two designs of antenna and matching structures coupled to the oscillator are developed and fabricated, the operating ranges 0.33 - 0.57 THz and 0.42 - 0.73 THz were obtained experimentally for these designs. The emission to open space was measured by an external superconducting receiver located in the separate cryogenic system.