Performance of a YBaCuO superconducting filter/GaAs low noise amplifier hybrid circuit

A superconducting 7.3-GHz two-pole microstrip bandpass filter and a GaAs low-noise amplifier (LNA) were combined into a hybrid circuit and characterized at liquid nitrogen temperatures. This superconducting/semiconducting circuit's performance was compared to that of a gold filter/GaAs LNA hybrid circuit. The noise figure characteristics of the superconducting filter/LNA hybrid circuit when compared to the gold filter/LNA hybrid circuit showed an improvement of 2.1 dB at 77 K. The gain characteristics showed an improvement of 0.5 dB for the high-temperature superconductor (HTS) filter hybrid over the gold hybrid at 77 K. >