Test cables must deliver high performance levels even when withstanding such daily abuses as being stretched, tugged, and sometimes used as handles for measurement equipment. Such cables can be expensive for lengths of just a few feet. However, when measurement integrity and the accuracy of test results depend on the cable, no price is too high. Still, for engineers who want the high performance without the high price tag, there are the new CBL-Series flexible coaxial test cables from Mini-Circuits (Brooklyn, NY). The CBL-Series cables are designed for stable phase, insertion-loss, and VSWR performance during and after flexure and large temperature swings (−55 to +100°C), over a wideband range of DC to 18 GHz (see figure).

These rugged test cables are constructed with a solid silver-plated copper-clad steel inner conductor. The outer conductor and two layers of shielding are formed with silver-plated copper flat-ribbon braid, aluminum-polyimide tape, and silver-plated copper braid. The conductors and shields are separated by a solid polytetrafluroethylene (PTFE) dielectric layer, while the entire cable is protected by a clear fluoroethylene polymer (FEP) outer jacket and connectors are reinforced with strain reliefs.

The CBL-Series test cables are available with a variety of male connector types, including SMA to SMA, SMA to Type N, and Type N to Type N connectors. The connectors are machined from passivated stainless steel, with gold-plated beryllium-copper (captive) center contacts and PTFE dielectric. Standard cable lengths are 2, 3, and 6 ft., although custom lengths to 100 ft. are available by contacting the factory. The company offers a six-month guarantee on the cable assemblies and will repair or replace any cable if the connector attachment fails within six months of shipment (the guarantee does not apply to cable or connector interface damage due to mishandling or abuse).

Standard length cables start at less than $70 for a 2-ft. assembly terminated on both sides with SMA male connectors, model CBL-2FT-SMSM. This assembly exhibits 0.4 dB typical insertion loss from DC to 2.5 GHz, 1.1 dB typical insertion loss from 6 to 12 GHz, and 1.4 dB typical insertion loss from 12 to 18 GHz. The return loss is typically 30 dB from DC to 2.5 GHz and typically 27 dB from 12 to 18 GHz. A 6-ft. cable with SMA connectors, model CBL-6FT-SMSM, exhibits 1.2 dB typical insertion loss from DC to 2.5 GHz, 3.0 dB typical insertion loss from 6 to 12 GHz, and 3.8 dB typical insertion loss from 12 to 18 GHz. The return loss for the 6-ft. SMA assembly is typically 30 dB from DC to 2.5 GHz and typically 27 dB from 12 to 18 GHz. Performance is similar with Type N connectors.

The CBL-Series cables are suitable as replacements for standard test-port cables, but also serve well in high-volume test applications and for cellular infrastructure site testing and general in-field RF testing. The cables are specified for operating temperatures from −55 to +105ºC; all assemblies are designed for use from DC to 18 GHz. P&A: $69.95 (CBL-2FT-SMSM, 2-ft. SMA-to-SMA cable) and up; stock. Mini-Circuits, P.O. Box 350166, Brooklyn, NY 11235-0003; (718) 934-4500, FAX: (718) 332-4661, Internet: www.minicircuits.com.