Development of a Coaxial Cable with High Transmission Rate and Low Loss

In aerospace and military fields, coaxial cables are typically required to be high temperature resistance, low loss and lightweight due to their harsh operating environments. Currently, coaxial cables specified by United States military standard (MIL-DTL-17) dominate the market. Using the smallest-sized RG196A/U coaxial cable as a benchmark, a high speed, high temperature resistant, low loss, and lightweight coaxial cable was developed in the study, with improvements in outer diameter, attenuation, and transmission rate. In theoretical model, characteristic impedance of the coaxial cable based on the design was 54.2 Ω, with a transmission rate of 82.2%. At frequencies of 200, 400, 600, 800, 1000 MHz, attenuation were all superior to RG196A/U. In production process, the coaxial cable was made by silver-plated copper wire, microporous polytetrafluoroethylene (PTFE) tape, polyimide (PI) copper foil, and perfluoroalkoxy (PFA). Test results showed that transmission rate of the coaxial cable could reach 87.6%, with attenuation improved by up to 28% compared to RG196A/U, while the outer diameter was only 1.5 mm, which could provide a new option for the application of coaxial cables in aerospace field.