Phase-locked oscillator at 3 mm waveband using high Tc superconductor mixer mounted on pulse tube crycooler

A frequency mixing and phase locking system is designed, in which electromagnetic shielding, microwave coupling, and intermediate frequency (IF) measurement arrangements are in- cluded. In lieu of liquid nitrogen, a pulse tube cryo- cooler is used to cool the whole system. With Jo- sephson grain boundary junction as the mixing ele- ment, the 96th harmonic frequency mixing at 3 mm waveband is obtained, and phase-locked voltage- controlled oscillator (VCO) is realized.