High Performance RF Jumper Cables

Today's mobile communications systems demand very low intermodulation (IM) characteristics due to the crowded frequency spectrum used by these services. As a result, components that have not traditionally been known as IM contributors have become IM sources to consider. RF cables and their associated connectors have been known to degrade a system's IM performance significantly and must be dealt with accordingly.

A new series of copper-corrugated jumper cable assemblies have been introduced that feature unique connector designs, solid center conductor cables and soldered inner and outer conductors. These cable assemblies exhibit consistent low passive IM (PIM) performance.

PIM for these cable assemblies is specified at –155 dBc (max) for third-order products and two-tone signals at 20 W per tone. The cables provide typical PIM of –160 dBc and testing to this criteria is available on a 100 percent lot basis on request. The jumper cables are designed and tested for an outside environment. The connectors are internally barrier sealed against water migration through the mated connector from other sources. A unique injection-molded boot on the connector back shell with an included O-ring ensures against water penetration from the cable joint.

A captivated O-ring seal between the coupling nut and the interior joint ensures against water penetration at the connector joint. No weather sealing is required when 7-16 DIN connectors are used and torqued to their specified value. The cables have been tested to a simulated water depth of 3 m per IEC529 and IP68 specifications.

The cable assemblies are specified at 1.1 (max) SWR at personal communications service frequencies using one right-angle connector and one straight connector. Lower SWR is obtained for cable assemblies using straight connectors on both cable ends or at lower frequencies. SWR testing is performed 100 percent for all cable assemblies.

Low profile right-angle connectors are available for use in many antenna installation configurations. These low profile connectors make near-flush antenna wall mounting as simple as pole mounting and provide lower loss than antennas with internal cables and bottom-mounted connectors. All the connectors are factory installed, soldered and sealed to provide the highest possible reliability. Figure 1 shows a cutaway view of a right-angle and straight connector mated pair. Figure 2 shows the straight connector mated pair.

All jumper cables are available in 0.5" super-flexible coaxial cable using copper-corrugated outer conductors. Standard cable assemblies use solid copper-clad aluminum center conductors for the lowest PIM compared to stranded center conductors.

Spinner GmbH,
Munich, Germany +49 (089) 12601-0

Precision Tube Co.,
Coaxitube Division,
Salisbury, MD (410) 546-3911.