FABRICATION OF ALL-NBCN FLUX-FLOW OSCILLATORS WITH A TAPERED SLOTLINEANTENNA AND OFF-CHIP DETECTION OF THEIR RADIATION POWER

All-NbCN flux-flow oscillators (FFO) with a tapered slotline antenna ( TSA) were fabricated on MgO substrates. A five-step microstrip transfo rmer was used to couple an FFO, which has a low impedance, to a TSA ha ving a high impedance, The microstrip transformers designed to have a return loss more than 20 dB at the center frequency. We have measured submillimeter wave radiation from the oscillators using an off-chip si licon-composite bolometer. Radiation from fabricated FFO was detected in a bias voltage range from 1.18 mV to 1.48 mV, which corresponds to a frequency range from 570 GHz to 710 GHz.