Making The Connection
When it comes to connectors, some manufacturers specialize solely in this component area. For the most part, however, cable and cable-assembly makers also deal in connectors.

Corning Gilbert, for example, offers a myriad of connectors for both the broadband and microwave arenas. Its "F"-series connectors permit a coaxial cable to maintain a 75-Ω impedance. These connectors are used with the 59, 6, 7, and 11 cable series. The UltraSeal and Ultra-Ease series of compression connectors boast low activation force in a high-performance compression connector. They promise to deliver superior RF shielding integrity and a complete seal to the cable jacket, thereby locking out moisture.

Astrolab, Inc. (Warren, NJ) designs and manufactures RF and microwave coaxial connectors for applications up to 65 GHz. Tensolite (St. Augustine, FL) also offers a robust line of connectors. This company recently introduced a new connector series with the same footprint as a standard-size 1 through 4 D-Sub. The RF-DSUB series promises up to a 50-percent increase in high-frequency RF-signal density with performance from DC to 40 GHz.

Another active participant in the connector arena is Huber+Suhner. This company just won an order for RF assemblies and connectors for the second series of 2376 Eurofighter Typhoon aircraft. The RF components will link the system's antennas, computers, transmitters, receivers, and other components that constitute the aircraft's Defensive Aids Sub System (DASS).

The Coax Surface Mount MID (CoS-MID) 75-Ω connectors from ITT Electronic Components (White Plains, NY) use molded-interconnect-device technology to integrate two, three, or four coaxial connector lines into a single surface-mountable module (Fig. 2) . As a result, both sides of the printed-circuit-board (PCB) card edge can be used. The four-line modules can be configured in a stacked 2 X 2 formation, which again doubles the line density. The 50-Ω SMA-connector range from ITT comprises straight and right-angle plugs and jacks for flexible coaxial cables, 0.141- and 0.085-in. semi-rigid and conformable cables, and PCB and flange-mount variants. These connectors promise to provide superior electrical and mechanically durable performance from DC to 18 GHz.

Interestingly, one connector company is solely dedicated to providing products that are no longer available. The Aviel Electronics division (Las Vegas, NV) of RF Industries can fabricate functional equivalents for most RF coaxial connectors and adapters that are obsolete, discontinued, or no longer available. The connectors are available in all common interfaces including SMA, SMB, SMC, MCX, and larger interfaces like BNC, TNC, N, C, SC, HN, LT, and LC. Typical body materials and contacts materials are used. Body configurations include straight, right angle, bulkhead, flange mount, blind-mate, tri-axial, and others.

Connector products are part of the long history of Winchester Electronics (Wallingford, CT). Among its newer products is the QC-SMA series, which incorporates a push/pull style of mating that does not require special tooling for mating/unmating. When mated, these connectors can rotate 360 deg. The QC-SMA plugs are fully intermateable with any standard SMA jacks or Winchester's SMA bulkhead jacks. The connectors' electrical performance is comparable to a standard SMA up to 6 GHz. Designs are available for both flexible and semi-rigid-type cables.

Quite a few newer product lines hail from Delta Electronics Manufacturing Corp. (Beverly, MA). The Delta MC-Card connectors can serve as an alternative to MMCX connectors in many wireless and telecom applications. These microminiature, 50-Ω impedance connectors offer snap-on coupling and a frequency range of DC to 6 GHz. They are best suited for use with cables in the range of 0.070 to 0.120 in. diameter as well as metric miniature cables. The connectors provide small size and light weight with the convenience of snapon mating and the ability to rotate connector pairs after mating for precise alignment.

Although the connector's design may seem to have been "perfected" by numerous expert companies, new, innovative approaches are always being developed. Andrew Corp. (Westchester, IL) just announced the Weathershield Connector Protection Enclosure family with a reusable weatherproofing system for cable connections. The WeatherShield Connector Protection Enclosures seal and protect the connections between 1/2-in. jumpers and devices, such as diplexers and tower-mounted amplifiers, from the environment. They also protect the in-line connections between 1/2-in. jumpers and 1 5/8-in., 1 1/4-in., and 7/8-in. coaxial-cable feeders. The one-piece weatherproofing enclosure provides a high-temperature-resistant, watertight seal around the connectors. It also helps to dampen vibration, which can loosen connector interfaces over time.

In the telecommunications arena, the SPOX Blind-mate Interface (BMI) connectors from Molex, Inc. (Lisle, IL) recently made news by offering a self-aligning feature in a small blind-mate package. The low-profile design allows for a mated stack distance of 11.00 mm (0.430 in.). A dual-row, panel-mount design on 2.50 mm (0.098 in.) centerline spacing provides rugged support for blind-mating applications and permits up to 3.00 mm (0.120 in.) misalignment between connectors— horizontally and vertically—prior to engagement. The headers are molded in LCP high-temperature plastic to meet lead-free-processing requirements. Firstmate/last-break circuits provide sequential engagement of contacts.

These numerous connector examples are just a tiny representation of the actual components that are available and the application areas that drive their development (see sidebar) . The same is true of the cables and cable assemblies that were spotlighted here. Cables and connectors are among the oldest product lines of the RF industry. Yet they remain dynamic. They are continuously being updated to support emerging technologies. As wireless technologies grow, expand, and become ever-more ubiquitous, transmission-line components will continuously evolve to support them. For a more complete listing of the companies that provide cables, connectors, and cable assemblies, please visit the Microwaves & RF Product Data Directory at www.mrf.com.