A microwave splitter for superconducting quantum circuits

Applications of up-to-date cryoelectronics, especially in quantum microwave engineering, require instruments that operating identically to an optical beam splitter. Using niobium technology for the application of thin film structures, we have fabricated a microwave signal power splitter with central frequency $f_0$ = 7.2 GHz. We have demonstrated experimentally that, in the 1-GHz band around central frequency $f_0$, the characteristics of the second and the third output ports are in the range of -3 $\pm$ 0.8 dB of the signal input power. The attenuation within power transfer from signal ports to the insulation port is 10 dB. The above-mentioned characteristics have been obtained at an operating temperature below the superconducting transition temperature.