PT Journal AU Loudkov, D Tong, CYE Blundell, R Kaurova, N Grishina, E Voronov, B Gol'tsman, G TI An investigation of the performance of the superconducting HEB슠mixer as a function of its RF슠embedding impedance SO IEEE Trans. Appl. Supercond. PY 2005 BP 472 EP 475 VL 15 IS 2 DE HEB mixer ER