The RF performance of long junction active devices using TlCaBaCuOstep edge structures

The authors report the fabrication of long, step-edge junctions using TlCaBaCuO with associated control lines that demonstrate strong modulation of critical current, usable current gains, large power gains, and fairly large bandwidths. The devices are operational at up to 95 K and RF measurements have been made at 77 K at frequencies up to a probe-limited 10 GHz. These four terminal devices have output impedances of 2-20 Ω, small signal current gains greater than 2.5, available power gains of over 10 dB from 0.5 to 10 GHz, and minimum noise figures of less than 1 dB