As wireless communication technology advances, coax connectors continue to play an important role in maintaining stable signal transmission in wireless networks, satellite navigation systems, and wearable devices. This article explains common coax connector types, key specifications, installation methods, and applications to help businesses compare options and select suitable connectors for their systems.

What Is a Coax Connector?

Coax connectors are electronic components used to carry radio-frequency, microwave, and other electrical signals between cables, circuit boards, and equipment. Depending on the application, they support cable-to-cable, board-to-board, or cable-to-board connections. Each coax connector must be compatible with the cable or board interface and meet the system’s specifications.

“Coaxial” refers to a structure in which the inner and outer conductors share a common axis. This arrangement helps reduce signal loss and electromagnetic interference, supporting reliable signal transmission.
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Coax Connector Structure and Components

A coax connector has a concentric structure, with a center conductor that carries the signal and an outer conductor that provides shielding to reduce electromagnetic interference and signal loss. The following describes the connector’s main components, from the inside out:

• Center Conductor: The center conductor carries the signal and typically takes the form of a metal pin or socket contact. It is commonly made of copper or a copper alloy with gold or silver plating.
• Insulator: The insulator separates the inner and outer conductors and holds them in position. Common materials include polytetrafluoroethylene (PTFE).
• Outer Conductor or Connector Housing: The outer conductor provides shielding against external electromagnetic interference and a ground connection, while the housing protects the internal components. Common materials include brass and stainless steel.
• Coupling Mechanism: The coupling mechanism determines how coax connectors mate and remain secured. Common options include threaded, bayonet, and push-on designs.

Common Coax Connector Types

BNC (Bayonet Neill–Concelman Connector)

BNC connectors use a bayonet coupling mechanism for quick connection and disconnection. To secure the connection, align the connector and rotate the coupling ring 90 degrees clockwise; no additional fastening tools are required. BNC connectors are available in 50Ω and 75Ω versions, with a typical upper frequency limit of approximately 4GHz. Common applications include oscilloscopes, signal generators, and broadcast systems, particularly where frequent connection and disconnection are required.

SMA (SubMiniature Version A Connector)

SMA connectors typically operate at frequencies up to 18GHz, while some higher-frequency versions support up to 26.5GHz or 27GHz. Their durable construction and threaded coupling help resist loosening and maintain a secure connection for stable signal transmission. SMA connectors are widely used in RF and microwave applications, typically have a 50Ω impedance, and are suitable for compact equipment such as antennas, RF modules, and drones.
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MCX (Micro Coaxial Connector)

MCX connectors are available in 50Ω and 75Ω versions. Standard models typically support frequencies up to 6GHz, while some versions support up to 10GHz. Their push-on coupling allows quick connection and disconnection, as well as 360-degree rotation while connected. Common applications include wireless communication systems, automotive GPS systems, digital TV receivers, and aerospace equipment.
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MMCX (Micro-Miniature Coaxial Connector)

MMCX connectors are miniature versions of MCX connectors and are approximately 30% smaller. Their snap-on coupling makes them suitable for applications with limited space, such as smartwatches, in-ear earphones, and compact antennas. MMCX connectors typically have a 50Ω impedance and support frequencies up to 6GHz. Like MCX connectors, they allow rotation while connected and offer easy installation and vibration resistance.
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N-Type Connector

N-type connectors are medium-sized coax connectors designed primarily for medium- to high-power equipment in outdoor and industrial environments. They use threaded couplings and are designed to resist water and dust. Common 50Ω versions support frequencies up to 11GHz or 18GHz, depending on the design. Typical applications include outdoor base stations, military systems, and rooftop RF antennas.
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Comparison of Common Coax Connector Types

（Mobile users can swipe the table left and right）

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How to Match Coaxial Cables with Coax Connectors

Most coaxial systems use a characteristic impedance of either 50Ω or 75Ω. Matching the impedance of the cable and connector helps maintain signal integrity across the coax connection. The following tables list common coaxial cable models and compatible coax connectors for each impedance category, helping businesses compare options for their applications.
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50Ω Coaxial Systems

A 50Ω coaxial system provides a balance between power handling and signal loss. Compared with 75Ω systems, it generally supports higher power while maintaining transmission efficiency. Many coaxial cables and coax connectors use this impedance, making it common in wireless communication and data transmission systems, including wireless networks, communication base stations, and GPS systems.

Common Cables and Connectors for 50Ω Coaxial Systems

75Ω Coaxial Systems

75Ω coaxial systems are designed to minimize signal loss during transmission. Although they generally have a lower power-handling capacity than 50Ω systems, their low attenuation makes them suitable for long-distance signal transmission, particularly in audio and video applications. Examples include 4K and 8K video distribution and HDMI extension systems that use coaxial cables.

Common Cables and Connectors for 75Ω Coaxial Systems

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How to Choose a Coax Connector: Three Key Selection Criteria

Using incompatible coax connectors can compromise signal transmission, shorten equipment service life, or cause damage. To choose a suitable coax connector, businesses should evaluate three key factors: operating frequency, power requirements, and environmental conditions.

Operating Frequency

Using a coax connector outside its specified frequency range can cause signal distortion and increased signal reflections, potentially affecting system performance. Excessive losses or reflected power may also contribute to overheating and damage. When selecting a coax connector, ensure that its rated operating frequency range covers the system’s requirements.

• Low-Frequency Applications (Below Approximately 3GHz): Coax connectors for low-frequency applications often use larger designs and are available in a wide range of types. Common examples include BNC and UHF connectors, with applications spanning cable television, wired internet, and radio communication systems.
• Mid- to High-Frequency Applications (Approximately 3–18GHz): Many coax connectors used in this range feature threaded couplings, including SMA, N-type, and TNC connectors. Applications include 4K video and audio transmission, as well as wireless communication systems such as Wi-Fi base stations, drones, and GPS antennas.
• Microwave and Millimeter-Wave Applications (Approximately 18–110GHz and Above): Coax connectors for these applications are often named after the inner diameter of their outer conductor. Smaller diameters generally support higher maximum frequencies. Common types include 3.5mm, 2.92mm (K-type), 2.4mm, and 1.85mm (V-type) connectors. Applications include RF and microwave systems, 5G/6G technologies, and low-Earth-orbit satellite systems.

Power-Handling Capacity

Power-handling capacity is a key consideration when selecting a coax connector. Its maximum power rating depends on operating frequency, connector size, dielectric material, ambient temperature, and structural design.

As operating frequency increases, conductor and dielectric losses generally increase, generating more heat and reducing the connector’s power-handling capacity. If the operating power exceeds the connector’s rating, overheating can damage the insulating material and potentially cause dielectric breakdown, short circuits, or connector failure.

• Low-Power Applications (Below Approximately 10W): Compact coax connectors are suitable for devices and systems with low power requirements, including smartwatches, Internet of Things (IoT) devices, and radio-frequency identification (RFID) systems. Common types include MCX, MMCX, and SSMP/SMPM connectors.
• Medium-Power Applications (Approximately 10–100W): Coax connectors for medium-power applications balance frequency performance and power handling, with designs that provide mechanical stability and heat dissipation. They are commonly used in communication equipment such as Wi-Fi routers, two-way radios, and drones. Common types include SMA, TNC, and BNC connectors.
• High-Power Applications (Above Approximately 100W): Coax connectors for high-power applications may handle hundreds or even thousands of watts, depending on the design and operating conditions. They are designed to accommodate high voltages and currents, with an emphasis on heat dissipation and mechanical stability. Common applications include telecommunications, meteorological systems, and military equipment. Connector types include N-type and 7/16 DIN.

Operating Environment

Environmental conditions affect the performance and service life of coax connectors. For outdoor installations, businesses should consider temperature, humidity, and exposure to water and dust. Connectors with IP67 or IP68 ratings may be suitable, depending on the application. For equipment exposed to significant vibration, such as drones and military or aerospace systems, threaded coax connectors such as SMA, TNC, and N-type can help maintain secure connections.

Coax Connection Guide: Cable Preparation and Connector Installation

Before installation, confirm that the coax connector’s characteristic impedance and dimensions are compatible with the coaxial cable. Common cable termination methods include crimp, solder, and clamp connections. The following steps outline how to assemble a reliable coax connection using a compatible cable and connector:

Step 1: Check All Connector Components

Before installation, check that all coax connector components are present and undamaged. Inspect the center pin for deformation and the insulator for dirt or cracks, as these defects can affect signal transmission quality.

Required tools depend on the termination method. Clamp connectors typically require standard tools such as open-end wrenches and diagonal cutters, while crimp connectors require a suitable crimping tool and die set. Ensure that the correct tools are available before starting.

Step 2: Strip the Coaxial Cable to the Required Dimensions

Carefully strip the coaxial cable’s jacket, shield, and dielectric to the dimensions specified in the connector’s assembly instructions, exposing the center conductor. Correct strip lengths help ensure proper contact with the coax connector’s center contact and prevent unintended contact between conductive components, reducing the risk of short circuits and signal reflections.

Step 3: Install the Insulator and Secure the Center Contact

The insulator separates the center conductor from the outer conductor, preventing direct contact and providing structural support. Secure the center contact and cable using the appropriate termination method: crimp connections use a crimping tool, solder connections use solder, and clamp connections use a nut and clamp ring. Follow the connector’s assembly instructions to ensure that each component is correctly positioned and secured.

Step 4: Assemble and Secure the Coax Connector

Once the center conductor and insulator are correctly positioned and secured, fit the remaining components into the connector body and secure them according to the coax connector’s assembly instructions. After installation, perform the required electrical safety and mechanical integrity checks. Put the completed coax connection into service only after confirming that the assembly passes these checks.
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Conclusion

Coax connectors come in a wide range of types, and the right specifications depend on the equipment’s operating frequency, power requirements, and intended application. Consulting an experienced coax connector supplier before purchasing can help businesses identify suitable options. Huang Liang Technologies has more than 30 years of experience in RF coaxial product research, development, and design, with products used across a range of industries. Contact us to discuss custom coaxial products and connection solutions tailored to your application.