Microwave Journal

New Coax Connector: Excellent Performance for Confined Spaces

September 12, 2019

Increasingly sophisticated services at ever faster data rates are being transmitted by high performance mobile radio networks, reflecting the modern mobile community’s unwillingness to put up with slow internet connections and poor quality voice, picture and video services. Today, everything must be fast - no matter what, no matter where. “Any service, anywhere, anytime” is the mantra. Service availability is no longer seen as a privilege, rather a right. Added to consumer expectations, fully or partially automated applications such as intelligent traffic control and autonomous driving require fast, secure and reliable connectivity. 5G is enabling these applications, unimagined just a few years ago, and 5G is driving dense, picocell networks. Space restrictions for these small cells are hampering the build-out of the infrastructure, which adds to the pressure on installers and operators. Limited space is problematic for antenna masts at the wireless access points and the cables connecting them.

1.5-3.5: Performance in Confined Spaces

To address this challenge of achieving performance in a small space, the new 1.5-3.5 generation of connectors offers an elegant and reliable solution. The 1.5-3.5 type delivers the performance of larger connectors in a significantly reduced size. Building on the success of the trendsetting 4.3-10 and 2.2-5 connectors, Telegärtner has developed the compact, high performance 1.5-3.5 connector for tomorrow’s mobile networks. This innovative connector achieves performance that, until recently, was not possible for such compact connectors. A typical 1.5-3.5 jack reduces the required mounting space by 47 percent compared to the compact 2.2-5 and an even more impressive 75 percent versus the 4.3-10 connector (see Figure 1). The 1.5-3.5 jack is available in two versions: either center-to-center spacing of 13 mm or a more compact 10 mm (see Figure 2).

Figure 1

Figure 1 The 1.5-3.5 is significantly smaller than the 2.2-5 and 4.3-10 connectors, making it well suited for small cells.

Figure 2

Figure 2 Two versions of the jack are available, with center-to-center spacing of 13 mm or, for tighter spaces, 10 mm.

Borrowing from its two “bigger brothers,” the 1.5-3.5 uses the popular and field-proven hexagon nut screw for extreme environmental conditions, and a quick, push-pull, self-locking mechanism for frequent plugging and unplugging - all usable on the same universal jack. The screw and hand screw versions are combined in one plug, allowing an installer to decide whether to tighten the connector by hand or with a torque wrench on site.

With the standard version, reliable signal transmission is guaranteed by a particularly low passive intermodulation of −166 dBc up to 6 GHz, measured with the standard two-tone 43 dBm signals. The response of the special version of the connector extends to 30 GHz. Despite its small dimensions, the 1.5-3.5 can transmit considerable power: up to 100 W at 2 GHz. The connectors have been engineered for more than 100 mating cycles, and the reliable design protects the plug contact against damage, even when unmated.

The plugs, available in straight and angled versions, are optimized for 0.25 in. corrugated cables, the jacks for UT 85, UT 141 and UT 250 Semiflex cables (see Figure 3). In addition to offering plugs and jacks as individual parts, off-the-shelf cables are available in standard and custom lengths for simple and time-saving installations (see Figure 4). A variety of adapters are also available for other connector series, such as the 4.3-10, 7-16, PC3.5 and N.

Figure 1

Figure 3 The plugs are optimized for 0.25 in. corrugated cables; the jacks for UT 85, UT 141 and UT 250 semiflex cables.

Figure 4

Figure 4 Off-the-shelf cable assemblies are available and can be made in custom lengths.

Whether screw, hand screw or push-pull, both connector variants offer IP68 protection and are suitable for harsh indoor and outdoor environments. An extended temperature range from −40°C to +85°C and a dielectric strength of 1.5 kV at 50 Hz makes the resilient high performance connector ideal for a wide range of applications needing a compact size. These include mobile radio networks, small cells, picocells, low power remote radio units and in-building wireless and distributed antenna systems. Installers, often working to tight schedules, will appreciate the many cable entry and locking possibilities. They can choose the best one for the project or application, whether the installation is in a compact space, at great height or facing rugged weather.

The new 1.5-3.5 connector has been developed for applications where high quality transmission is required and cabling and installation space is limited. Despite being comparable in size to SMA connectors, the 1.5-3.5 connector is PIM-stable and suitable for outdoor use. The straight and angled cable outlet variants and the screw and push-pull locking mechanisms enable trouble-free installation in locations where no other connector can be used.

Telegärtner Karl Gärtner GmbH
Steinenbronn, Germany