The Ultimate Coaxial Cable Connectors Guide

Coaxial cable connectors are just as critical as the cables themselves. They create secure mechanical connections between cables and devices and preserve signal integrity and overall performance.

Using the wrong connector can result in unstable connections, impedance mismatches, poor EMI shielding, and even physical damage. This can lead to electrical or fire hazards.

This guide will help you avoid these risks by explaining what coaxial connectors are, the different types available, their specifications, and how to choose the right one for your application.

What are Coaxial Cable Connectors?

Coaxial cable connectors terminate coaxial cables, replacing the need for manual splicing or soldering. They simplify installation and ensure secure, reliable connections. One of the first factors to consider when selecting a connector is its gender.

Gender

You must be able to tell cable connectors by their gender to install your coaxial cables successfully. 

• Male Connectors: These connectors feature protruding conductive cores (pins) that allow you to fit and attach them to corresponding female connectors. They are also commonly referred to as “plugs.”
• Female Connectors: They have a threaded outer sleeve or barrel lined with an insulating layer on the inside. They are identified by their central sockets, which are designed to dock male connectors, ensuring optimal signal transmission and safety.  
• Genderless Connectors: These combine aspects from male and female connectors into a single unified package and are typically made to be attached to other genderless connectors of the same type. An example is the APC-7 connector, which facilitates connections through its retractable threads. Some designs may allow a genderless connector to “mate” with a female or male connector. However, unlike gendered connectors, genderless connectors are designed for bidirectional signal transmission.     

Because female connectors tend to be more robust than male connectors, they’re commonly placed on devices acting as ports. Male connectors, on the other hand, are typically affixed to the endpoints of coaxial cables. Most coaxial cable connectors use a bolt and nut-like mechanism, allowing technicians to tie male connectors to female connectors with their hands. However, these aren’t the only available mating types.

Polarity

Apart from the gender classification, you can also classify these connectors based on their polarity. Most applications use standard polarity, while others use RF connectors with reverse polarity (RP). This is mainly done to limit the usage of non-approved radio antennas based on FCC (Federal Communications Commission) rules and regulations.

RP (Reverse Polarity) RF connectors can be confusing because they resemble standard polarity connectors of the opposite gender. However, you can identify the difference using the following tips:

• RP male connectors have threads on the inner side of the shell, but will have a central hole like female connectors. 
• The RP female version will have threads on the shell’s outer surface, but with a center pin similar to a male connector.

The central pin separates standard polarity from reverse polarity connectors. In standard polarity configurations, the male acts as a plug, and the female acts as a jack. Conversely, reverse polarity configurations feature a male acting as a jack and a female acting as a plug.

Termination Options

Before a connector can be applied to coaxial cable, it must be sufficiently terminated. Terminators make it easier to affix the connector onto the cable. Coaxial cables feature similar but very distinct termination options, with the most common types being: 

• Twist-On Terminations: Feature a screw-on or lug structure. While it can make installation easier, it can also lodge air pockets in the connection points between the cable and connector. This may negatively impact the signal quality.
• Tabs: Cost-effective options that offer a quick, secure fit. Although easy to connect, they’re susceptible to misalignments and may not be compatible with all coaxial cables.
• Compression Connection: This involves placing the coaxial connector’s outer shell onto a cable and compressing it, creating a secure, tight fit. These connections are extremely reliable and are often used in telecommunications and aerospace.    
• Crimp Terminations: A technician squeezes the connector onto the cable with a crimping tool, creating a tight, secure fit. 
• Solder Terminations: Where the connector is fastened and secured onto the coaxial cable using solder. This creates a secure mechanical and conductive bond. 

Which Industries Use Coaxial Cable Connectors?

Coaxial connectors are implemented wherever coaxial cables are, primarily in areas requiring high-speed data transmissions with minimal interference. 

• Communication and networking
• RF and microwave systems
• Military and defense
• Test and measure
• Medical equipment
• Aerospace
• Audio and video equipment
• Automotive Electronics

Types of Coaxial Cable Connectors

As discussed in the previous section, coaxial cable connectors are used across many industries and come in various shapes, orientations, and types to suit different applications. The most common types include:

Standard RF Connectors

Standard-sized connectors are designed for RF applications such as radar systems, networks, and outdoor installations. 

• Type N: Feature gaskets to prevent water and air from contaminating the conductive elements of the connector and cable. The base version can support frequencies of up to 11 GHz and impedances of 50 Ohms. Some specialized designs (such as those for CATV) can operate at 18 GHz with an impedance of 75 Ohms. 
• 7-16 DIN: High-frequency connectors designed for applications that require low intermodulation distortion (IMD). For instance, antenna systems in cellular networks. The IP680-rating version of this connector allows it to be used in outdoor installations. 
• 2.4 mm connectors: Screw-on precision connectors designed with an operating range of up to 50 GHz and an impedance of 50 Ohms, allowing them to ensure minimal signal loss. This makes them ideal for high-frequency applications such as test and measurement equipment.
• 2.92 mm (K) connectors: Offer an operating range of up to 40 GHz and an impedance of 50 Ohms. They’re compatible with SMA and 3.5 mm connectors. You can typically find these connectors in testing equipment and aerospace systems.      
• 3.5 mm connectors: They have a screw-on interface, an operating range of up to 34 GHz, and an impedance of 50 Ohms. You can find them in many of the same applications as 2.92 mm connectors and 2.4 mm connectors.    
• 7 mm connectors: Deliver an operating frequency of up to 18 GHz and an impedance of 50 Ohms. Because they feature low reflection levels, they’ve found extensive usage in calibration equipment, microwave components, and semi-rigid cabling.                   

Miniature RF Connectors

These are high-performance connector types with a small form factor. They’re best for applications in mobile communications and automotive systems. 

• BNC (Bayonet Neill-Concelman) Connectors: They have a unique bayonet locking mechanism, which makes them easier to install and remove. With an operating frequency of up to 4 GHz and available in impedance packages of 50 and 70 Ohms, they’re used mainly in video systems and test equipment.      
• MHV (Miniature High Voltage) Connectors: These connectors have a structure and locking mechanism similar to BNC connectors but can support higher operating frequencies and voltages. They can have operating frequencies as high as 300 MHz and a peak voltage rating of 5000V. Typical applications include Geiger counters, X-ray devices, high-voltage power supplies, and nuclear control instrumentation.       
• Mini-UHF: compact variants of the standard UHF connectors. They use threaded coupling and have a frequency range up to 2.5 GHz.   
• TNC (Threaded Neill-Concelman) Connectors: Their threaded locking mechanism ensures optimal, stable connections. They have an operating frequency range of up to 11 GHz, which can be extended to 18 GHz. They are available in 50-ohm and 75-ohm impedance ratings.  

Sub-miniature RF Connectors

These connectors are best for high-frequency applications where space is an issue. This is why they’ve found such wide usage in telecommunications, instrumentation, and wireless systems. 

• Subminiature Version A (SMA) connectors: Feature precision connectors with threads for mating and an operating range up to 18 GHz.   
• Subminiature Version B (SMB) connectors: These connectors feature snap-on connectors for easy, quick attachments and an operating range of up to 4 GHz. 
• Sub-Miniature Version C (SMC) connectors: Threaded connectors with an operating range with a limit of 10GHz. 
• SSMA and SSMB connectors: These are smaller versions of the SMA and SMB connectors, built for ultra-compact use cases. The SSMA connector can operate up to 34 GHz, while the SSMB is limited to 4 GHz.  
• SMP and SMPM connectors: These are high-frequency connectors with a push-on interface for blind-mating. Because they can operate up to frequencies as high as 65 GHz, they are ideal for radar and satellite systems.  

Micro-Miniature RF Connectors

Micro-miniature coaxial (MMCX) connectors are some of the smallest ones available. They’re roughly 30% smaller than subminiature version B (SMB) connectors, making them ideal for applications with considerable space limitations. 

They have a frequency range from DC to 12 GHz, which allows them to be used in phones, cellular base stations, and two-way radios (walkie-talkies). They can also be found in other personal networking applications such as GPS and wireless LAN (WLAN). 

Other RF Connectors

• Type C Connectors: These connectors feature a dual-stud bayonet connection mechanism that offers excellent weatherproofing. They have a frequency range of up to 11 GHz and an impedance of 50 ohms. They are suitable for military applications, aerospace, and test and measurement equipment. 
• FME: RG-58 coaxial cable connectors that are specifically designed for mobile applications. They feature a threaded coupling and an impedance of 50 ohms. They typically have a frequency of DC to 200 MHz.  
• SC: Medium-sized coaxial connectors designed for high-frequency applications. They can operate up to 11 GHz and have impedance ratings of 50 Ohms, making them ideal for high-frequency test equipment and secure RF connections in defense systems. 
• Tri-ax connectors: Feature a triple-conductor interface, allowing them to handle high voltages, with some capable of handling 5000V peak. They’re available in threaded and bayonet coupling styles.   
• Twin-ax: Features a polarized keyway design that prevents signal mix-ups while ensuring proper mating. They’re used in instrumentation, military, and broadband applications. 
• UHF (PL259): Threaded RF coaxial connectors designed for old radio transmission. They can’t maintain a consistent impedance of 50 Ohms and only have operating ranges of 300 MHz. Consequently, they’re primarily used in high-frequency (not ultra) applications such as citizen band communication setups and amateur radio setups.      
• 1.6 / 5.6 DIN Connectors: Found in push-pull and threaded configurations. They can operate in frequency ranges from DC to 1 GHz.     
• 1.85 mm (V connectors): Threaded precision coaxial connectors can operate at frequencies up to 67 GHz. They have an impedance of 50 Ohms.  

Choosing the Right Coaxial Cable Connector

Choosing the right connector depends on matching its performance specifications and features to those of your coaxial cable.

Performance specification

The connection option will impact the performance of the coaxial cable. 

• Impedance: A cable’s value is determined mainly by its resistance to electrical signal flow. Lower resistance, measured in ohms, generally means better performance. For example, a 50-ohm cable offers less resistance than a 75-ohm one. However, lower resistance is not always better. The ideal resistance depends on the specific requirements of your cable assembly project.
• Frequency range: The range at which the coaxial connector can transmit signals. Depending on the connector, it can be as low as DC to 300 and be as high as 67 GHz. 
• Insertion loss: Describes how much strength a signal loses when a connector is attached. A low insertion loss is best.  
• Voltage rating: Refers to the maximum voltage a connector can handle without breaking down or leaking. Some connectors can handle voltages as high as 5000V.
• Shielding effectiveness: Relates to the amount of electromagnetic interference (EMI) a connector can protect against. 
• Durability: Refers to how long a connector lasts. It is usually displayed as mating cycles (usually 500+).    

Features

You can enhance the performance of your coaxial cable assemblies with additional customizations.

Environmentally resistant

• Hermetic seals: Completely resistant to gases.
• Gaskets: Protect against fluids and humidity.

Industry Standard

• Sterilization-Compatible: Various connectors are available for use in hospital settings based on their validation for different sterilization methods.

Plating material

• Gold: Delivers excellent conductivity and resistance against corrosion, but is usually saved for high-performance connectors because of its expense.
• Silver:  The best conductor on the market, but not as effective against tarnishing and oxidation as gold.
• Nickel: Manufacturers use it to create a barrier between copper and gold plating to prevent tarnishing caused by these materials coming into contact.
• Copper: A highly affordable conductor with an unfortunate weakness to corrosion. Manufacturers don’t often use it as a plating material. Instead, they use it in the core conductive element in cables or connectors.  

Geometry 

• Straight: For direct non-angular connections.
• Right-angled: Used mainly in applications with minor space constraints.  

Wiringo Can Handle Your Coaxial Cable Connector Needs

We recommend carefully evaluating all RF connector factors when designing your cable assembly. A single misstep can cause performance issues or system failure. We provide custom coaxial cable and RF wiring solutions for a wide range of industries, focusing on efficient data transmission and seamless integration.

We offer a wide selection of coax cable types to match all your needs. This includes semi-rigid, Radio Guide (RG) braided, micro-coaxial, and hand-conformed cables. In terms of coax connectors, you can choose from our range of Standard (1.85mm, 1.0mm, 2.92mm, 10-32, 2.4mm, F, N, SMA,  DIN 7/16, 4.1/9.5, etc), Miniature, Sub-Miniature, Micro-Miniature, and Specialized options. They’re available in various geometries, sizes, and customizations, including male and/or female cnfigurations with straight or right-angled orientations. 

Contact us today to learn more about our products and how we can help you with your coaxial cable connector needs.