The primary factor restricting power handling in the coaxial adaptor or connector is overheating due to restricted heat dissipation. High power cable assemblies, in general, should not exceed 200°C, however dielectric materials used in precision connector interfaces like 7 mm and 3.5 mm are only rated to 90°C. Astrolab manufactures a high temperature precision bead for high power applications. The maximum temperature usually occurs on the connector inner conductor. When connectors are employed in a coaxial cable assembly, the connector should have a center conductor diameter that is equal to or larger than the cable center conductor diameter in order to maximize the power handling of the assembly.

Although many applications support the use of standard connectors and coaxial transmission lines, recent designs in TWT’s, high power filters and high power test equipment have placed a great burden on standard coaxial cable assemblies. Since the internal configuration of the connector termination is a major contributor to heat buildup, Astrolab employs a unique dielectric material known as Fluoroloy H^® inside connectors used for high power applications. This material has a slightly higher dielectric constant (compared to standard Teflon^® dielectric) but has a higher rate of thermal conductivity which allows the heat that is generated in the center conductor to transfer to the outer conductor more rapidly, thus increasing the power handling capability of the connector or adaptor. The majority of Astrolab connectors and adaptors can be produced with Fluoroloy H^® dielectric upon request. In addition, Astrolab can design special customized high power interfaces that are mechanically and electrically compatible with standard interfaces. Contact Astrolab sales department regarding any high power requirements.

Note: Teflon^® is a trademark of Dupont; Fluoroloy H^® is a registered trademark of Saint Gobain Corp.

Engineering Home | Back | Next