I. A. Korzh, V. N. Zima, M. A. Evdokimov

The paper deals with prospective building methods of power RF attenuators. One of the methods is tree-structured connection of film planar resistors that results in uniform distribution of separable heat rating and furthers transfer from fluid- to air-cooling. The authors have carried out comparative analysis of backing materials used in power film resistors producing as well as metal base materials for these backings. Tantalum films were used as a resistance base because of their advanced stability and linear heat expansion coefficient like in ceramic plates. As a result, backing materials (aluminium nitride) and resistor cores (pseudoalloy) with optimum performance were chosen and the design and manufacturing methods of film tantalum resistors for high power RF attenuators are presented. The authors also propose the design of low- and high-value resistors on the ceramic substrate. The structure of RF attenuator module is presented.