RF Cable Connectors: Your 2021 get-to-know Guide

FACTS CHECKED BY  Jose George​

Did you know that RF cable connectors have a gender? Also, the type of connector varies depending on the device? If all this sounds foreign to you, do not worry. The information below will get you sounding like a pro in no time. Here is a quick overview of what they are, the different types, and how to select the right one for your project. 

What is an RF Cable Connectors?

It is an electrical connector that allows radio frequencies to work at multi-megahertz ranges. You will find them in use alongside coaxial cables that attach to devices such as routers and TV set-top boxes. For example, the metal thing at the end of the cable that connects your television and outdoor antenna is an RF cable connector.

RF Connector

Initially, their function was to maintain the shielding of the cable. However, newer models can now minimize signal reflection and loss of power. Additionally, they also block external interference from electromagnetic signals and captive pickup. Furthermore, RF cable connectors come with a fastening mechanism that allows for better contact between the cable and device. For example, router cables feature a thread mechanism for their RF connectors.

Types of RF cable connectors you can buy

Cable connections come in different varieties, and so do RF cable connectors. The type of connection you use will depend on the application. Currently, these are the seven types of connections you will find in common use. These are:

RF cable connectors
  • TNC, also known as a Threaded Neill-Concelman connector.
  • Bayonet Neill-Concelman connector (BNC)
  • SMB or Subminiature Version B
  • QMA
RF cable connectors
  • RCA 
  • 6/17 DIN
RF cable connectors
  • MCX

You find more on each connector type and its applications by reading the piece on coaxial cable connectors.

RF Cable Connectors – Gender and Polarity

RF Connectors

RF cable connectors can either be male or female, depending on the device’s connection. The easiest way to distinguish them is by looking at their design features. Male connectors or plugs have a pin in the center and fastening threads inside their shell. Conversely, female connectors, also known as jacks, have a socket in their center. Additionally, the fastening threads are on the outer casing that covers the center.

Polarity refers to the electrical properties of each connection. It can either be positive or negative, depending on the device and connector type. In normal polarity connections, the male connectors have a center pin with fastening threads on the outside. However, there are instances where reverse polarity works best. For example, WiFi routers have reverse polarity connections. Male connectors have sockets for their centers, but the threading remains on the inside of the casing.

When choosing which connector to use, there are three things you need to be aware of:

  • Your connection will only work if the connectors have similar polarity.
  • The best connection is between connectors. For example, a BNC connector will only work with a BNC connector.
  • Finally, a male connector can only connect to a female connector. However, you can use a coaxial adapter to bypass rules two and three.  

How do you choose RF Cable Connectors?

As you can see, RF connectors come in different varieties. Therefore, it is important to know what connection works best for you. Here are the important things to consider when choosing an RF connector.

Impedance

Impedance is the amount of resistance to the electrical current compared to the energy flow when you apply voltage to the circuit. In RF connections, each connector offers a specific impedance limit for it to function well. The standard impedance limit in most connectors is 50 ohms. However, you can still find others that allow for an impedance level of 75 ohms. For example, the connection between your outdoor aerial and television offers a 75 ohms impedance.

Frequency range

Radio frequencies travel in a wave-like pattern from source to receiver. The limits may vary depending on the type of connector and current flowing through the circuit. You can get anywhere between 20 kHz to 300 GHz frequency range depending on the connector type you use. For example, a BNC RF connector can get you a frequency range of up to 10GHz, unheard of in UHF connectors.

Despite this impressive capability, not all BNC connectors you will buy can reach these levels. Therefore, you must check the manufacturer’s specifications before you commit to a purchase. Finally, always source for connectors from reputable manufacturers, as these adhere to the latest industrial production and quality standards.

Power handling

The contact between the plug and jack needs to be damaged and dirt-free for your connection to work seamlessly. Additionally, the material that makes up the contacts determines how well your connection will handle the power. For example, high power handling connectors feature either a gold or silver plating on their jacks and plugs.

Coax cable compatibility

There are things that naturally go together. Similarly, the type of connector you use will depend on the type of cable. Always buy a connector that matches the dimensions and diameter of the cable in use.

Voltage

The power requirement of the circuit will determine the amount of voltage that it needs. Simply put, you need to use a connector that has a favorable voltage allowance to cater to any fluctuations when your device is in operation. Another thing to consider is environmental conditions. They too, affect how well your connector can manage voltage levels.

Straight or Right-angled?

You may be wondering why this is an issue? But, the cable layout and connection type can either enhance or hinder performance. Straight connections offer the best functionality. The signal travels a lesser distance, and there is minimal insertion loss. Additionally, you get a lower voltage standing wave ratio with straight connectors. Therefore, always refer to the manufacturer’s datasheet when buying an RF Connector.

Connector plating

Radiofrequency connectors come in a variety of finishes. You can get them in silver, nickel, or gold, depending on the level of performance you desire. As the frequency level increases, most of the current concentrates on the outer surface of the conductor.

Consequently, you experience a decrease in performance due to most of the signal reflecting outwards. Nickel only offers a thickness of 0.71 nanometers which is not ideal for RF signals. Therefore, you are better off with gold or silver-plated connectors as these give you skin depths of 2.4 and 2.0 nanometers, respectively. 

Conclusion

RF connectors are an essential device in today’s digital world. The above information offers you insight into their functionality, design, and applications in everyday life. You can find more on cable assemblies and connectors by clicking on this link.

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