High-temperature superconducting resonator-stabilized coplanar hybrid-integrated oscillator at 6.5 GHz

A small-size coplanar oscillator has been designed and entirely fabricated on a 10-mm*10-mm/sup 2/ LaAlO/sub 3/ substrate in superconducting microwave integrated circuit (SMIC) technology. As an active element, a GaAs MESFET has been used. The oscillator is stabilized by a coplanar waveguide transmission line resonator patterned from a YBa/sub 2/Cu/sub 3/O/sub 7-x/ film onto the LaAlO/sub 3/ substrate. The oscillator, operating at 77 K, is characterized by a center frequency of 6.5 GHz and a power output of nearly 5 dBm. A single-sideband phase noise to carrier ratio of -90 dBc/Hz at 10-kHz offset has been attained. The attenuation of harmonics is better than 10 dBc.<>