A solution to the problem of design and technological optimization (DTO) of resonant-tunneling diodes (RTDs) based on the electrical parameters of nonlinear frequency converters (FCs) is proposed to ensure their reliability in given operating conditions. A software package has been developed that makes it possible to perform an analysis of the reliability of FC microwave radio signals based on RTDs and to carry out DTO of the electrical characteristics of the FC in order to ensure reliability under specified operating conditions The developed software complex is tested on a wideband RTD-based balanced microwave frequency mixer. It was revealed that performing DTO on the mentioned mixer allows us to increase its gamma-percentage resource by 7.5 times, which proves that DTO is a perspective way to ensure RTD-based FC reliability.