A miniature quick connect/disconnect radio frequency (RF) connector known as a Bayonet Neill Concelman (BNC) connector is used with coaxial cables in a 10Base-2 Ethernet system as well as for radio frequency and video applications. Due to their ease of use and high performance, these connectors are some of the most popular RF connectors.
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What Does BNC Connector Mean?
In place of coaxial connectors, the Bayonet Neill-Concelman Connector (BNC connector) is a coaxial RF (Radio frequency) electrical connector type.
A BNC connector is used in electronic architectures like audio, video, and networking to connect various radio frequencies up to 3GHz and voltages under 500V DC. Due to its low-signal-loss architecture, BNC is also utilized in high-grade analog communications test equipment and avionics. Nearly always, BNC connectors are used to terminate coaxial ethernet cables.
Types Of BNC Connectors
BNC connectors typically come in four different varieties:
- Twist-On
- F-Compression Connector
- F-Crimp Connector
- Crimp-On
Twist-on BNC
This kind of connector is easy to use and doesn’t need any special tools because, as its name suggests, you just twist it onto the coax cable to attach it. If the cable is not first stripped, tools may, of course, be required. Despite the misconception that twist-on BNCs are unreliable because they do not attach as firmly as crimp-on or compression connectors, they can function properly when the cable is properly prepared.
F-crimp Connector
The F-Crimp connector technique is similar to the F-compression connector technique, but it uses a crimp-on connector rather than a compression one. A screw-on BNC connector is attached to the cable after an F connector, just like with method number 2 above.
F-compression Connector
There are two methods for installing BNC compression connectors: 1) use a one-piece A compression F connector was attached to the coax cable before the BNC compression connector was screwed on. Since the coax core is visible in the second method and there is no need to guess the length, there is very little room for error. This is why many installers prefer it. Many installers also favor method two because F-connectors can be used to install most TVs as well as surveillance systems (the Mammoth Security office in Middletown, CT can assist you with this). This indicates that they are not only able to eliminate at least one more piece of material during a typical run, but also that they are exceptionally skilled at what they do because they do it frequently.
Crimp-on Connector
Additionally, there are two variations of the crimp-on BNC connector: 2-piece and 3-piece. 3-piece is rarely used, so for the sake of this article, we’ll just discuss the 2-piece method. Using the 2-piece BNC crimp-on connectors, installing cables requires the following two tools: a crimping tool and a cable stripper. The end result is a secure connection and cables that are not likely to come loose any time after installation, despite the fact that this process takes a little longer than any of the others.
History Of BNC Connectors
In order to create a high-quality connector that could handle a variety of applications, BNC connectors were initially developed in the late 1940s. The inventors, Paul Neill and Carl Concelman of the Amphenol Corporation, and the bayonet mount locking mechanism were honored with the name. A bayonet knife mount found on the end of rifles is used by the close-fitting locking mechanism.
The Bayonet Neill Concelman connector is the proper name for this connector, which is also occasionally referred to as a Berkeley Nucleonics Corporation connector, Bayonet Navy Connector, Baby N Connector, British Naval Connector, and British National Connector. Although it was initially created for military use, it has since become popular for use in RF and video applications.
Octavio M.’s work served as the inspiration for Neill and Concelman’s connector. A connector for coaxial cables was developed in 1945 by Salati of the Hazeltine Electronics Corporation, which decreased wave reflection and loss. This was accomplished by joining across the cable’s radial surface rather than a terminated cross-section. At a flat cable end, cross-sections experience signal degradation due to reflection. His creation received a patent in 1951.
While employed at Bell Labs, electrical engineer Paul Neill also created the N connector. In order to handle microwave frequencies, he set out to build a coaxial connector. By keeping the distance between the outer shell and the center conductor connection as close to the feedline dimensions as possible, his N connector was able to maintain its characteristic impedance. The weatherproof structure had male and female threads that matched in its outer shell and sockets. Still in use today is this kind of connector.
While employed by Amphenol at the same time, electrical engineer Carl Concelman created the C connector. Similar to how the N connector maintained its characteristic impedance, Concelman’s connector did as well. However, he focused on usability by using the bayonet quick-disconnect structure rather than the screw and unscrew connection. The two connections would then be locked together after the outer shell was rotated to move the lugs into the inner shell’s short arm of the groove.
Then, Neill and Concelman collaborated to create a connector that combined the best elements of both of their creations as well as Salati’s work. The BNC connector, which employs the same strategy for maintaining impedance and adopts the bayonet-style connection, is essentially a miniature version of the N connector and C-type connectors. The size of BNC connectors is the biggest difference between them and C and N types.
The LEMO 00 mini-connector, which supports higher densities, is replacing the BNC connector, which is still widely used in electronics. Additionally, higher density in video broadcasting is made possible by the HD-BNC connector and the DIN 1.0/2.3.
BNC Development
The BNC connector was developed in the late 1940s and it gains its name from a combination of the fact that it has a bayonet fixing and from the names of the designers, the letters BNC standing for Bayonet Neill Concelman. In some references, it has also been stated to stand for Bayonet Navy Connector.
The C connector, which was a bayonet version of the N-type connector, was essentially a miniature version of the C connector, which is what the BNC connector is.
The need for a high-quality, durable connector that could be used in a wide range of applications led to the development of the BNC connector. Additionally, it needed to be smaller than the much larger N-type or C-type connectors.
BNC Specifications
It is best to make sure the specific component being purchased is suitable for the intended application because the BNC connector’s specifications naturally differ from manufacturer to manufacturer. There are a few rules that can be followed, though. There are two basic types of connectors available:
- 50 ohm
- 75 ohm
The 50 ohm version of the BNC connector is the more popular of the two versions. The BNC connector is frequently designed to operate at frequencies up to 4 GHz, but it can also operate at frequencies up to 10 GHz if the special, high-quality versions designed for that frequency are used. To thoroughly review the specification is still a good idea.
BNC Connector Performance
For both low-frequency and DC circuits, nearly any standard connector can transfer current over a mechanical link. On the other hand, radio frequency calls for a connection that will minimize changes in impedance, which might otherwise result in reflection and damaging standing waves. Coaxial cables have a characteristic impedance that allows them to carry radio frequencies.
BNCs are constant impedance connectors, meaning that their characteristic impedance is the same throughout the entire connection and is comparable to that of coaxial cables. Because RF signals traveling along a coax cable will not experience any changes in impedance as they pass through the BNC connector, there will be fewer reflections and a lower level of loss, making BNC connectors ideal for RF applications.
BNCs are male connectors with pins at each end to connect to the main conducting wire. For locking the cable to any female connector, they have a rotating ring outside the tube. If the cable is pulled, this locking mechanism prevents unintentional disconnecting. This secure connection is made possible by two different kinds of locking mechanisms:
- The twist and snap: this design with interlocking studs and slots is designed for quick mating. An effective connection is indicated by the audible “snap.”
- Triggered Nut Coupling (TNC): this is a threaded version of BNC with screw threads for a secure connection rather than a locking pin and slot.
BNC connectors can handle up to 4 GHz but are typically used with voltages and frequencies below 500 volts and 3 GHz. The following characteristics are typically shared by all BNC connectors, though they can vary depending on the manufacturer:
- Frequency Range: Up to 11 GHz (0 – 4 GHz with low reflection)
- Impedance: 50 Ohms, 75 Ohms
- Dielectric Voltage Resistance: 1500 VRMS
- Mating Cycles: 500
- Temperature Rating: -65°C to +165°C
- Diameter (Male): 14.0 mm / 0.570 in
- Diameter (Female): 11.1 mm / 0.436 in
- Coupling Mechanism: Bayonet Coupling
- Interface Standards: CECC 22121, IEC 61169-8, MIL-STD-348B
BNC Connector Uses
The most widespread uses of BNC connectors are in radio frequency and video functions, including test equipment, nuclear instrumentation, aerospace electronics (avionics), radio antennas, and serial digital interface video signals.
On commercial video devices, the BNC connector can be used in place of the RCA connector to transmit composite video signals. A BNC adapter is frequently required to connect consumer electronics with RCA jacks to BNC commercial video equipment.
BNC connectors are additionally utilized in recording studios for the transmission of word clock timing signals, which synchronizes various pieces of digital recording equipment.
BNC Connector Formats And Variants
There are numerous formats available for BNC connectors. Along with plugs and sockets, other items like attenuators and adapters are also available.
In addition to having the necessary impedance, BNC plugs are made to take a specific coax cable format. All internal components are thus compatible with the coaxial cable being used. Because of this, it is essential to specify the BNC plug for the cable to be used. Even though there is some flexibility, it is best to choose the appropriate cable format.
There are additionally straight and right-angled variations. The most common type of connector among these is straight, though right-angled connectors, in which the cable exits the plug at an angle to the center of the connector center line, are also available. These are perfect for a variety of uses where it’s important for the cables to exit the connector neatly or where there is limited space. Unfortunately, compared to straight through connectors, right-angled connectors have a slight increase in loss. For the majority of applications, this might not be a big deal, but at frequencies close to the connector’s operational limit, it might make a little difference.
There are numerous variations of the sockets or female BNC connectors. The most fundamental BNC connector consists of a panel mounting assembly with a single connection for the coax center. The connector is then fastened to the panel with a single nut, completing the earthing process. An earth connection can be made directly to the connector using large washers. Four nuts and bolts may be used to secure some of these connectors to the panel. These configurations aren’t appropriate for RF applications; only low frequency ones. where full screening and impedance matching are necessary. It is possible to do this by using bulkhead mounting connectors with a coaxial cable entry. Once more, these come in a variety of cable dimensions, so the right kind should be used.
The BNC connector assembly process has two main iterations:
- Compression gland type
- Crimp type
BNC Assembly
Depending on the application, there are various BNC connector assemblies. Another factor contributing to this connector’s popularity is its adaptability.
BNC Twist-on Connector
Only the cable is needed to connect the twist-on BNC connector. The cable connector can be attached by hand-twisting.
BNC Compression Connector
An F connector with one piece is known as a compression connector. For cable modems and satellite TV, an F connector is a coaxial radio frequency connection. With a cable stripper and compression tool, they can be quickly connected to the cable.
BNC Crimp-on Connector
A BNC crimp-on connector can be safely connected to a coaxial cable using a cable stripper and compression tool. There are 2-piece and 3-piece versions of the commonly used crimp-on technique.
BNC Inserter/remover Tool
A lightweight, stainless steel tool called a BNC inserter/remover tool is used to apply torque when inserting or removing BNC connectors. They are made to quickly and safely connect or disconnect BNC connectors in high-density, difficult-to-reach locations without running the risk of unintentionally compromising or harming neighboring connectors.
Best BNC Connector Vendors
Beyond what was originally intended, a wide range of industries have adopted the BNC connector. BNC connectors are produced by numerous electronics companies as a result. Among the most common are these:
- BELDEN
- ESCAM
- Rconector
- ANPWOO
- Smar
- PEGATAH
