Choosing the Right RF Connector for Your Application

A coaxial RF connector (radio frequency connector) is an electrical connector designed to work at radio frequencies in the multi-megahertz range. RF connectors are typically used with coaxial cables and are designed to maintain the shielding that the coaxial design offers.

Are you struggling to determine which RF connector type is best suited for your application? Don’t worry—you’re not alone! This article will guide you through the different types of RF connectors and their common uses.  

RF (radio frequency) connectors are specialized connectors designed for high-frequency signal transmission in devices such as radios, antennas, and coaxial cables. With various types available, selecting the right one is crucial for optimal performance.  

5 Most Common RF Connector Types  

Here are five of the most widely used RF connectors:  

- Type N Connectors – Known for their durability and weather resistance, commonly used in telecommunications and radar systems.  

- UHF Connectors – Designed for low-frequency applications, often used in CB radios and public address systems.  

- TNC Connectors – A threaded version of BNC connectors, offering better performance in higher-frequency applications.  

- BNC Connectors – Popular in RF testing, video transmission, and signal processing due to their quick-connect design.  

- SMA Connectors – Compact connectors widely used in wireless communication systems and antennas.  

1. Type N Connector  

The Type N connector is a threaded, weatherproof RF connector designed for rugged applications. It supports frequencies up to 11 GHz and complies with MIL-STD-348 standards. Due to its durability and cost-effectiveness, it is widely used in low-frequency microwave systems where reliability is essential.  

2. UHF Connector  

The Ultra High Frequency (UHF) connector is a threaded RF connector capable of handling frequencies up to 100 MHz. Unlike Type N connectors, UHF connectors lack waterproofing and do not provide a constant impedance. They are commonly used in amateur radio, Citizens Band (CB) radio, and marine VHF radio applications.  

3. TNC Connector  

The Threaded Neill-Concelman (TNC) connector is a threaded version of the BNC connector, offering superior performance at microwave frequencies. TNC connector is frequently used in radio communication and wired applications where secure connections and enhanced frequency performance are required.  

4. BNC Connector  

The Bayonet Neill-Concelman (BNC) connector is a miniature quick-connect/disconnect RF connector primarily used for low-frequency applications. Originally developed for military use, BNC connector has since become widely adopted in composite video transmission, commercial video equipment, and RF applications up to 2 GHz.  

5. SMA Connector  

The SMA connector (SubMiniature version A) is a semi-precision coaxial RF connector that operates at frequencies up to 18 GHz, with some proprietary versions reaching 26.5 GHz. It is commonly used in RF power amplifiers, RF isolators, microwave systems, mobile phone antennas, WiFi antenna systems, and radio astronomy (5 GHz and above).  

5 Key Factors in Selecting RF Connectors  

Now that you understand RF connectors and their types, let’s explore the essential factors to consider when choosing the right one. These include coupling mechanism, electrical performance, environmental suitability, and cost.  

Material and Construction  

RF connectors vary in material quality, with commercial-grade options using cost-effective materials and military-grade ones offering higher durability. Common conductor materials include brass, copper alloys, and stainless steel with gold, silver, or nickel plating. Insulation is typically made of PTFE, PP, HIPS, or PEI. The choice of materials affects performance, insertion loss, and longevity.  

Size also matters—standard, miniature, subminiature, and micro connectors cater to different applications. Selecting the right size minimizes signal reflection, while miniaturized connectors work well in compact devices but may wear out faster with frequent use.  

Different coupling mechanisms, such as bayonet, threaded, push-on, quick-lock, and snap-on, suit various needs. Threaded connectors are the most vibration-resistant, while bayonet and push-on types allow quick connections.  

Electrical Parameters  

RF connectors operate within specific frequency ranges, so selecting one that aligns with your application is essential. SMA connectors, for example, are versatile due to their broad frequency range.  

Impedance matching is also crucial for minimizing power loss. BNC and F connectors are commonly used for 75-ohm applications, ensuring efficient signal transmission.  

Environmental Factors  

Consider temperature resistance and environmental exposure. Outdoor applications require moisture and corrosion-resistant connectors to maintain durability and reliability in harsh conditions.  

Compatibility and Standards  

Ensure the connector type matches your existing system in both mechanical fit and electrical parameters. If necessary, use an RF adapter for compatibility between different connector types. Compliance with standards such as MIL, DIN, BS, IEC, and IEEE is also important for project requirements.  

Cost  

Budget considerations play a role in selection. SMB connectors tend to be more expensive, while N-type and BNC connectors offer a more cost-effective solution.  

Summary

RF connectors come in various types and are widely used in high-frequency applications. Understanding relevant knowledge is essential for the selection and utilization of suitable RF connectors. Also, proper maintenance helps keep your RF connectors in good condition.