For optimal performance above 500 MHz you should use semi-rigid coax cable; used in aerospace and defense, test & measurement instruments, medical electronics, and space flight systems among other rigorous, precise applications.
Winchester’s semi-rigid coax is built and tested to meet the MIL-DTL-17 (MIL-C-17) performance requirements. We can build and supply bulk cable as well as custom configured bent semi-rigid assemblies at our fully equipped ISO-certified facilities.