Microwave test cables often lead a stressful life. The seemingly tranquil benchtop environment can harbor many hazards, including engineers and technicians who over-flex cable assemblies, over-torque their connectors, and cram cables into drawers. To withstand these stresses, test cables are manufactured for ruggedness, while maintaining low loss as well as good phase and amplitude stability. Unfortunately, some flexibility is often sacrificed when trying to build cables to meet these other requirements. The ULTIMATE UTiFLEX cables from MICRO-COAX (Pottstown, PA) are designed to address this problem by remaining flexible, but also keeping their shape once bent. This dramatically reduces stress and eliminates the need for any support along their length.

The ULTIMATE UTiFLEX family of cables is available in two basic models, with mode-free performance from DC to either 40 GHz or 65 GHz (see table). Their ability to maintain a specific shape once formed is a result of special armoring that provides a "memory" effect. The result is that easily-damaged devices can be tested without the weight of the cable at their interfaces. It also can extend the time between calibrations, since the continuous bending most precision test cables face is dramatically reduced.

The armoring capability of the cables does not preclude them from being flexed during testing, with no adverse effects on performance (see figure). To ensure that the cables meet their rated specifications, each cable assembly is tested for amplitude and phase stability by bending the cable around a mandrel at its minimum specified bend radius and evaluated for any change in phase or insertion loss.

The armoring itself provides protection against kinks, dents, and other damage, and can withstand 100 lb./linear in. of crush resistance, a tensile load of 100 lb. in a static test, and tortional resistance. The 40-GHz ULTIMATE UTiFLEX test cables employ 2.92-mm ruggedized connectors and the 65-GHz cables have ruggedized 1.85-mm connectors. Both are available in 18-, 24-, and 36-in. lengths. MICRO-COAX, 206 Jones Blvd., Pottstown, PA 19464-3465; (610) 495-0110, e-mail: info@micro-coax.com, Internet: www.micro-coax.com.