Microwave Nonlinearities in Thin Superconducting Films

Abstract

A thin superconducting Sn film is placed across the opening of an X-band waveguide, so that the opening is completely covered. In a certain power range, the film transmission is found to be highly nonlinear, and third harmonics of the iundamental frequency are generated. No detectable second harmonic is generated. The film is unbiased. The waveguide frequency is 9.4 kMc. (T.F.H.)