K.I. Rudakov - Student, MFTI. E-mail: rudakov@hitech.cplire.ru
V.P. Koshelets - Dr.Sc. (Phys.-Math.), Head of Laboratory, Kotel-nikov Institute of Radio Engineering, and Electronics Russian Academy of Sciences. E-mail: valery@hitech.cplire.ru

Comprehensive studies of the electrical parameters of superconducting microwave structures made with different materials of the upper electrode (Nb, NbN, and NbTiN) have been performed in order to determine the various microwave parameters of these structures. To solve this problem we have used numerical methods for calculation of the microwave matching. The ultimate goal of these researches is development and study of integrated spectrometers in the range of 400-1200 GHz with ultimate (quantum) sensitivity. We have measured test samples with different materials of the upper electrode. The method and technique that take into account parasitic capacitance of the tunnel SIS (superconductor  insulator  superconductor) junction and the spreading inductance have proposed and verified. Electrical parameters of the experimental structures have been estimated: London penetration depth for Nb is 85nm, for NbN- 350nm, for NbTiN  320nm, the effective dielectric constant  4.2).