A Complete Guide to Coaxial Connectors

Coaxial or coax cables are electrical cables created to carry high frequency, multi-megahertz electrical signals. They contain an inner conducting wire, usually copper, surrounded by a protective double insulating layer and then an outer plastic sheath, giving them a distinctive appearance.

Coaxial cables are durable, easy to install, and have a broad range of uses. Their design allows rapid signal transmission (around 10 megabits per second) with minimal electro-magnetic interference or signal loss. Coaxial cables are the default cabling choice for many low voltage consumer electronics.

These include:

• Televisions and telephones
• Mobile phones
• Satellite dishes
• Broadband routers
• Antennas
• Radio equipment

Coaxial cables are available in a variety of types, distinguished by their gauge and impedance. Gauge refers to the thickness of the cable and is given a given a Radio Guide or RG number, with higher numbers indicating thinner conducting cores. Impedance refers to the level of electrical resistance in the wire. Most coaxial cables have an impedance of either 75 or 50 Ohm. The former is primarily used for video signals and the latter for data.

Coaxial cables can come in many sizes, including:

• RG-12
• RG-58
• RG-62
• RG-213

Coaxial cables are used for many different purposes and so the connectors are equally varied. Each type and size is carefully designed to mesh seamlessly with the host cable and function in different, sometimes quite tough conditions. They must resist stressors such as impact, pressure, high temperature and vibration.

Coaxial cables made for radio frequency (RF) transmission require special connectors that provide consistent electrical resistance at the point of connection with connected cables. This means that they are somewhat delicate and can be damaged easily.

The major types of coaxial connector are as follows:

Coaxial connectors are used for a wide range of applications in various industries as they provide multiple advantages. Some of their key advantages include:  

• Reliable signal transmission – coax cable connectors are able to maintain strong and stable signal transmission over long distances whilst losing minimal signal. The design of coaxial connectors boasts an inner conductor shielded by an insulating layer and an outer shield. This helps to reduce electromagnetic interference.
• **Durability – **coaxial connectors are a robust type of cable that can usually withstand demanding conditions. They’re also made from materials like gold-plated metals which prevent corrosion, leading to a longer service life.
• Cost-effective – compared to other connectors coaxial connectors are relatively cheap, and their durability helps keep down maintenance and replacement costs.
• Easy to install – whether it’s by crimping, soldering or push-through methods, coaxial connectors are relatively simple to install, making them very user-friendly. In addition to this, as they’re a common connector, the tools and equipment needed to install them are both widely available and affordable.
• Versatility – coaxial connectors can be used in multiple fields from security systems to telecommunications and networking. They are designed to work well across a range of different frequencies, which is why they are a common choice within RF and high-frequency systems.
• Strong performance – the coaxial connector provides a mechanically secure connection that reduces the risk of loose connections or signal interruptions. Their reliability is further boosted thanks to the locking mechanisms typically used by the connector which prevents accidental disconnections.

Coaxial cable connectors are essential for dependable signal transmission in systems that need high-frequency, low-loss connections. Here are just a few examples of industries where coaxial connectors are priceless:  

Coaxial connectors are widely used in the telecommunications sector, especially in satellite and cable TV (CATV) systems. With the help of coaxial connectors, high-quality audio and video signals can be sent across great distances with little interference. TV and satellite systems frequently use F-type connections because they offer a dependable, safe connection that maintains signal integrity even in harsh conditions. Broadband internet networks also use coaxial connectors to help provide families and businesses with fast internet access. 

Coaxial connectors are widely used in audio and video equipment. A popular choice of connector is the BNC, which is often used for production and broadcast equipment such as on TV sets and concert venues as it provides a robust connection, handling high frequency signals without signal degradation, ensuring video signals remain clear and stable.  

CCTV systems often use coaxial connectors as they offer a stable and high-quality connection between cameras and recording devices. This is critical for capturing clear footage. As established above, BNC connectors are a popular choice for ensuring video signals remain clear and stable, so they are a common choice in security systems too.  

Coaxial connectors are an essential piece of equipment in RF communication networks and Ethernet systems as they can transmit data over long distances securely with minimal loss. Coaxial cables and connectors can ensure that large volumes of data can flow efficiently by establishing a stable connection between network devices.  

Due to the robustness and durability of the coaxial connector, they are often deployed in military and aerospace applications, such as aircraft, satellites and defence equipment. They can withstand demanding conditions which include extreme temperatures, vibrations and other challenging conditions, which makes them an ideal option for this industry.  

When selecting a coaxial connector, you will need to know the key parameters of the cable you plan to connect. These include:

• The voltage
• The environment
• The required frequency
• Whether a male or female connection is required. Male connectors have protruding metal pins while female connectors have a recess designed to receive the pins

Coaxial Connector Gender Types

In electrical engineering, coaxial and other electrical cables are conventionally divided into two types: male and female. The former typically have a connecting pin or protrusion of some kind that is inserted into indentations or slots in the latter – for example, plugs and sockets (also known as jacks). Connecting a male to a female connector is referred to as ‘mating’ them.

Coaxial cable genders were designed not just to allow physical connections but also to ensure that power or signal data flows in the correct direction, from male to female connectors with matching electrical polarity, preventing interference and unsafe installations. Typically, female connectors are more resistant to damage than male ones so these tend to be placed in crucial areas with males relegated to connecting cables, which can be replaced more easily.

Note that the terms ‘male’ and ‘female’ are not universally used, especially in relation to lower voltage domestic appliances. Widely used electrical standard IEC60320 does not specify gender types for the latter.

Male Coaxial Connectors

Male coaxial connectors typically have a straightforward design, combining a central pin designed to fit a compatible plug on the female connector, alongside a spring-loaded electrical contact point located at the side.

Female Coaxial Connectors

Female coaxial connectors normally feature a metallic tube designed to precisely contain the corresponding male pin, normally called the tip. This is surrounded by an insulating layer and then an outer cylinder, typically referred to as the barrel or sleeve. The latter functions as an electrical contact point, alongside the inner tube.

Genderless Coaxial Connectors

Genderless coaxial connectors combine male protrusion points and female slots in the same connection point, enabling these to be connected to either male or female connectors of matching size and type. They allow cabling within complex installations to be repurposed or reconnected quickly, without awkward removal and repositioning if it needs to be connected to a different component or cable. They have a reverse electrical polarity, with a pin protruding from the female socket and slot in the male plug designed for that pin.

Genderless coaxial connectors are also known as combination connecters. They are not the right choice for installations in which a carefully controlled flow of current in a single direction is required for safety or functionality reasons.

Despite the rise of more modern transmission methods, coaxial connectors continue to play a crucial role in emerging technologies and remain indispensable in several industries: 

• 5G networks – coaxial connectors provide the effective transmission of high-frequency signals, which is essential for 5G technology's extremely fast data speeds and low latency. They’re used in base stations, antennas and small cell systems.
• Broadband and smart cities - coaxial connectors are widely used for last-mile connections, delivering high-speed internet to homes and businesses. Additionally, they are integral to smart city networks, enabling communication between sensors, devices, and systems for improved urban management.
• Autonomous vehicles - Coaxial connectors support the connection of sensors, cameras, and radar systems in autonomous vehicles, which is necessary for processing data in real time.

How Do You Connect or Change a Coaxial Connector?

Coaxial cables and their corresponding connectors have different uses but the fundamentals of connecting or replacing them remain much the same. Here is how to conduct this procedure:

1. Ensure that the cable is removed from any power sources. Electrical shocks and injuries could result from adjusting a live coaxial cable
2. If there is already a connector in place, remove it. It may respond to a simple twist or you may need to make use of a tool such as a construction knife or wire strippers
3. Prepare the coaxial cable, using a wire stripper or similar device. Make a small incision towards the end of the cable, deep enough to expose the underlying copper, and then a second cut in the outer jacket of the cable – in both cases being careful not to cut into the underlying layers. Use these cuts as leverage to peel back the jacket and then the wire braiding beneath, going back the same length as the connector
4. Place the connector onto the exposed length of wire
5. Attach the connector to the wire by applying pressure. Use a compression tool – for example, a pair of pliers – or a more specialist crimping tool. Crimping is only a modified form of compression, so the two methods are very similar. In both cases, insert the connector which has been placed over the cable into the tool and apply firm pressure. Finally, spray liquid electrical tape to any remaining exposed areas and allow this to dry

What are Micro Connectors?

Micro-coaxial connectors are made for the smallest cables – typically not exceeding 1.5cm in diameter and less than 6 GHz. Their small size makes them well suited for use in complex but physically small electronics such as mobile phones, GPS receivers, Wi-Fi routers, and PC equipment.