The latest developments in high-frequency cables and connectors seek to cut weight while maintaining low loss and high phase stability even in flexible assemblies.
Cables and connectors are usually only noticed when they fail. At their best, they can add nothing electrically to a system or a circuit but, at their worst, they can degrade amplitude and phase performance. Recent developments in these interconnection components have been aimed at making them as electrically "invisible" as possible, with low loss and the best possible impedance match to a 50-Ohm system.
For example, coaxial cable assembly supplier Electronic Assembly Manufacturing, Inc. (EAM) recently announced that it was offering high-performance flexible cable assemblies for applications through 20 GHz (see figure). Based on T-Flex cables from Times Microwave Systems, a 3-ft.-long assembly built with 0.141-in.-diameter cable and SMA male connectors exhibits 1.35:1 VSWR from 45 MHz to 18 GHz. The 50-Ohm flexible cable assemblies, with stable attenuation and phase characteristics over time, meet all MIL-C-17 requirements. The cables feature polytetrafluoroethylene (PTFE) dielectric with silver-plated copper tape and braid shield and fluorinated ethylene propylene (FEP) jacket. The cables can be terminated with a variety of connectors, including SMA, BNC, 7/16, SMP, and TNC connectors.
Response Microwave is now offering its TESTCABLZ family of cable assemblies for production test applications through 18 GHz. The flexible cable assemblies include 0.163-in.-outside-diameter or 0.104-in.-outside-diameter cables with choice of male and/or female SMA, push-on SMA, Type N, TNC, BNC, MCX, or SMC connectors in straight and right-angle configurations. The typical attenuation is 0.30 dB/ft. with maximum VSWR of 1.20:1 and RF leakage of -110 dB. The cables have an FEP jacket over silver-plated copper with PTFE dielectric and silver-plated copper-clad steel center conductor.
Dynawave recently added low-loss bulk cables to its product lines, covering applications from DC to 65 GHz. According to the firm's Vice President and General Manager, Bob Thiele, "By adding bulk cable to our product line, Dynawave continues to expand its capabilities to the RF and microwave market. Our customers will appreciate the opportunity to work with one trusted source that can offer them a broad range of electrically matched cables and connectors for their most demanding applications."
Crystek Corp., a company perhaps better known for its crystal oscillators, introduced a line of low-loss flexible coaxial cable assemblies with stainless-steel solder-clamp construction. The LL142 series cables offer a minimum bend radius of 0.8 in. with better than 110 dB shielding effectiveness (SE) and attenuation of 0.36 dB/ft. at 18 GHz. The cable assemblies are available with SMA, Type N, and TNC connectors.
Micro-Coax weighed in with its new UTi- FLEX MCJ185A space-grade cable for applications through 32.3 GHz. The lightweight cable is rated for operating temperatures of -200 to +150C and is validated to the full qualification requirements of MIL-DTL-M17. The cables, with 0.08 dB insertion loss at 1 GHz and only 0.5 dB insertion loss at 32 GHz, are low outgassing and radiation-resistance cables that have passed the full qualification requirements of MIL-DTL-39012. They weigh only 12.4 g/ft.