1.What Is an SMA Connector?
An SMA connector (SubMiniature version A) is a compact RF coaxial connector first developed in 1958. It features a threaded coupling mechanism and a characteristic impedance of 50 ohms, making it one of the most widely used RF connectors in high-frequency applications.
Thanks to its small size, mechanical stability, and excellent electrical performance, the SMA connector is commonly used in wireless communication, antennas, GPS systems, RF modules, and microwave equipment.
2.SMA Connector Frequency Range and Key Specifications
One of the main reasons for the popularity of SMA connectors is their wide frequency capability.
Typical SMA connector specifications:
• Impedance: 50 Ω
• Frequency range: DC to 18 GHz (some precision SMA up to 26.5 GHz)
• Coupling type: Threaded
• Plating: Gold-plated (standard), nickel-plated for thicker cables
• Cable types: RG174, RG316, RG58, etc.
SMA connector power handling depends on frequency and cable type. At lower frequencies, SMA connectors can handle higher power, while power capability decreases as frequency increases.
3.SMA Male vs Female: How to Identify Them
Understanding SMA male vs female is critical to avoid connection mistakes.
• SMA Male (Plug):
○ Has Internal threads
○ Features a center pin
• SMA Female (Jack):
○ Has external threads
○ Features a center socket
Tip: Do not rely only on thread direction—always check the center contact.
4.Standard SMA vs RP-SMA: What’s the Difference?
RP-SMA (Reverse Polarity SMA) connectors reverse the gender of the center contact while keeping the same outer threads.
|
Type |
Threads |
Center Contact |
|
Standard SMA Male |
Internal |
Pin |
|
RP-SMA Male |
Internal |
Socket |
|
Standard SMA Female |
External |
Socket |
|
RP-SMA Female |
External |
Pin |
RP-SMA connectors are widely used in WiFi routers and antennas to meet regulatory requirements.
5.Common SMA Connector Applications
SMA connectors are used across many industries, including:
• RF and microwave communication systems
• GPS and GNSS devices
• WiFi and Bluetooth antennas
• RF test equipment
• Aerospace and military electronics
Their secure threaded design makes them suitable for vibration-resistant environments.
6.How to Choose the Right SMA Connector (Buying Tips)
When selecting an SMA connector, consider the following factors:
• Frequency requirement – ensure the connector supports your operating range
• Cable compatibility – RG174, RG316, or custom cables
• Gender & polarity – SMA vs RP-SMA, male vs female
• Mounting type – straight or right-angle
• Application environment – indoor, outdoor, or industrial use
Choosing the correct SMA connector ensures signal integrity and long-term reliability.
7.FAQ: SMA Connector Basics
Q1: What is an SMA connector used for?
A: SMA connectors are used for high-frequency RF signal transmission in antennas, RF modules, GPS, and wireless systems.
Q2: What is the SMA connector frequency range?
A: Standard SMA connectors support up to 18 GHz, with precision versions reaching 26.5 GHz.
Q3: Are SMA and RP-SMA compatible?
A: No. They look similar but have different center contacts and are not interchangeable.
Elecbee specializes in RF connectors, adapters, and antenna solutions, offering OEM-quality SMA connectors with competitive pricing.
If you need help selecting the right SMA connector for your application, feel free to contact us.
