What are 4.3-10, 2.2-5, 1.5-3.5 connectors?

By AJ Born

Meet the Connector: 4.3-10, 2.2-5, 1.5-3.5 Connectors

The size of the connectors has often determined the footprint of antennas and base stations. As demand for miniaturization increased, the 4.3-10 connector system was designed to be smaller, while maintaining excellent electrical performance and lowering passive intermodulation (PIM). 2.2-5 and 1.5-3.5 followed as even smaller versions for new mobile communications applications.

The 4.3-10 connector is a 50 Ω multi-purpose RF connector developed as a replacement for the 7/16 DIN connector, which had been the industry standard for cellular networks. The 4.3-10 connects coaxial cables with RF devices, such as transmitters or antennas, or with other cables.

Due to the minimization of antennas and base stations, their footprint size quite often was dominated by the size of the connectors. The task of creating a smaller connector system was initiated by leading mobile equipment vendors Ericsson, Kathrein, and Nokia Siemens Networks. The goal was to meet the rising performance needs of mobile network equipment and at the same time reduce its size in support of the ongoing space reduction requirements. The best proposals from connector suppliers were put forward and the result was the joint development of the 4.3-10 connector system by RF connector manufacturers Rosenberger, HUBER+SUHNER, Spinner, and Telegärtner in 2013.

4.3-10 connectors from Rosenberger.

4.3-10 connectors from Rosenberger.

One of main advantages 4.3-10 has over the 7/16 DIN connector is its smaller footprint that was achieved by reducing the outer conductor diameter from 16 to 10 mm. This lowered the power rating but allowed a connection density of one connector per inch. It fit perfectly in between existing connector systems used in the mobile communication industry. 4.3-10 shines with best electrical performance and lowest passive intermodulation (low PIM).

The new design, decoupling the electrical contact from the mechanical fastening interface, reduced the high torque requirements (25-30 Nm) for the DIN 7/16. As a result, it can be offered with screw, hand-screw, and push-pull mechanisms that simplify installation effort.

The 4.3-10 replaced the axial O-ring gasket with a radially loaded O-ring set into the grove of the male plug’s outer conductor. This significantly reduced PIM issues related to installation. However, stress is increased on the smaller gasket, which may be damaged more easily.

Similar in performance to the 4.3-10 connector, the DIN 2.2-5 is less than half the size (about the size of a TNC). This specification, also developed by connector companies including Molex, Amphenol, and Telegärtner, has a cutoff frequency of 16 GHz, but current applications are generally in the range of 6 GHz to 8 GHz.

Smaller still is the1.5-3.5 series of robust low-PIM connectors for 5G small cell and other communication box applications. Telegärtner was the first company to offer this connector. While similar in size to SMA connectors, the 1.5-3.5 series connectors require 47% less space than the 2.2-5 and 75% less space than the 4.3-10 connectors yet can transmit power up to 100W at 2 GHz. They are used for applications up to 30 GHz that require durability and miniaturization.

Shown here, Rosenberger‘s  NEX10 connectors. Rosenberger, Radiall, and HUBER+SUHNER have jointly developed the latest small form factor, low-PIM, RF connector series that is custom-tailored for 5G small cell mobile networks. An alternative to 4.3-10, NEX10 RF connectors are perfect engineering solutions for wireless connectivity requirements including macro cell sites, metro cells, and distributed antenna system (DAS) deployments.

Design Notes

For 4.3/5

Coupling: Hex-wrench, hand tighten, and quick-release. One jack type can mate to all plug types.

Standards: Standardized in 2016 as IEC 61169-54 and updated in 2021 as IEC 61169-54:2021.

Impedance:  50 Ω

Frequency range: DC to 12 GHz

Return loss: 38 dB; 2,5 GHz – 32 dB

Minimum pitch: ≥ 25.4 mm

PIM: ≥ 166 dBc @ 2x43dBm

Mating cycles: 100

For 2.2-5

Coupling: threaded or push-pull coupling mechanisms. They can mate using screw, push-pull, or hand-screw types.

Standards: Standardized as IEC 61169-66:2021.

Impedance:  50 Ω

Frequency range: Up to 20 GHz (special version)

Return loss: Up to 6 GHz – 36 dB

Minimum pitch: ≥ 25.4 mm

PIM: ≥ 166 dBc @ 2x43dBm

Mating cycles: 100

For 1.5-3.5

Coupling: push-pull (no tools required) and screw-on variants (requires a tool with recommended torque of 1 Nm).

Standards: Does not have an IEC standard.

Frequency range: up to 30 GHz

Return loss: up to 6 GHz – 32 dB

PIM: -166 dBc @ 2 x 43 dBm

Mating cycles: >100

IP classification: IP68 makes it suitable for indoor and outdoor applications.

Markets and Applications

Datacom/Telecom

4.3-10 – Cellular networks, RRU to the antenna, splitter and filter systems, plug-in chassis systems

2.2-5 – Small cell equipment, DAS (distributed antenna systems), MIMO (multiband antennas)

1.5-3.5 – Wireless infrastructure applications, Pico cell applications, DAS, telematics in vehicles, and harsh environments subject to extreme temperature fluctuations, humidity, and dust.

Suppliers

Rosenberger, Amphenol RF, Fairview Microwave, HUBER+SUHNER, Pasternack, Spinner, Telegärtner.

Related products

NEX10

SMB/SMC

SMA Connectors

Miniature & Ultraminiature RF Connectors

Low-PIM connectors

Like this article? Check out our other Meet the Connector and Networking articles, our Datacom/Telecom Market Page, and our 2023 and 2024 Article Archives

Like this article? Check out our other Meet the Connector and Miniaturization articles, our Sensors/Antennas Market Page, and our 2024 Article Archives

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AJ Born
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