HIGH-POWER COAXIAL MICROWAVE LOAD Russian patent published in 1997 - IPC

FIELD: high-frequency power absorbers; terminal loads of coaxial lines. SUBSTANCE: load is, essentially, section of multilayer coaxial line shorted out on one end and open on other one; internal conductor of coaxial line is formed by cylindrical thin-film absorber placed in cylindrical dielectric tube in a spaced relation to allow coolant flow between them. External transforming conductor has gradually reducing sectional area towards shorted-out end of line section. External conductor shape on three-layer line section is to be found from equation , where d_i are diameters of media interfaces in three-layer coaxial line d₁<d₂<d₃<d₄; ε_i is relative dielectric constant of respective layer; x is cross-sectional area coordinate counted from shorted-out end of line section; L is absorber length; R is absorber resistance; z_o=120 Ohms is wave impedance of free space. External conductor diameter in double-layer line of load terminal section may be constant and dielectric tube thickness may reduce towards shorted-out end of load. EFFECT: improved basic performance characteristics of coaxial load built around thin-film absorber: improved absorbed power level, extended matching frequency range. 4 cl, 10 dwg