Difference between SMA connectors and SMB connectors

Both SMA connectors and SMB connectors are very common connector types and ultra-small RF coaxial connectors. This leads that a lot of procurement staff new to RF series connectors cannot accurately distinguish them. To distinguish between SMA connectors and SMB connectors quickly and accurately, we will introduce the differences between SMA connectors and SMB connectors in detail.

Here is the content list:

l Difference in impedance

l Difference in frequency range

l Difference in characteristics

l Difference in shape

l Difference in caliber

Difference in impedance

1、Different connectors have different impedances, generally only 75 ohms and 50 ohms. They can be selected according to their required impedance.

2、SMA connector is a threaded connection of a small RF coaxial connector. Its characteristic impedance is 50 ohms. An SMB connector is a small push-in RF coaxial connector developed and produced according to Mil-C-39012 standard. It has two characteristic impedances, including 50 ohms and 75 ohms.

Difference in frequency range

1、SMA connectors have a frequency range of 0-18Ghz. They are widely used in aerospace systems, microwave communication engineering, and military weapons fields. SMA connectors have become the world's most versatile, with the largest variety of specifications, and the largest amount of RF connectors. One of the advantages of SMA connectors is the use of very high frequency. Such connectors use threaded connections, and SMA connectors of precision grade can be used even up to 26.5 GHz. For example, our SMA connector RG174 from LenoRF is available at frequencies up to 18 GHz.

2、However, the frequency range of SMB connectors is 0-4GHz. SMB connectors are widely used in communication equipment, instrumentation, and navigation systems with operating frequencies from 0 to 4GHz. It is also used in the connection of RF or digital signals between PCB boards and within PCB boards. The frequency of SMB connectors is relatively low.

Difference in characteristics

1、Although SMA connectors and SMB connectors are relatively small, they both have slightly different characteristics.

2、SMA connectors were invented in 1958 by James Cheal, then they were used to solve the problem of TEM mode conversion between coaxial and microstrip, with a simple structure, wide operating band, high reliability, and other characteristics.

3、The SMB connector is a push-in connector with a stop, which was developed in response to the market demand for quick plugging and unplugging of connectors. The centering function of outer conductor shrapnel and overlapping insulators make SMB connectors easy to snap and maintain good performance in a vibration environment. It has the features of easy plugging and unplugging good vibration resistance, and small space occupation.

Difference in shape

1、In fact, the shape of connectors mainly depends on their own needs and the requirements of manufacturers, which can be customized. To avoid confusion, the production will deliberately avoid producing the same shape as the connector. Therefore, SMA connectors and SMB connectors have slightly different shapes.

2、The shape types of SMA connectors are mainly divided into straight, 90-degree radial type or 90-degree right angle several, and press-in, bulkhead, 2-hole-flange or 4-hole-flange SMA connector.

3、While the shape types of SMB connectors are mainly divided into straight or 90-degree right angle type and bulkhead, 2-hole-flange, 4-hole-flange, or no installation type.

Difference in caliber

Because of the different connection methods and interface construction, the caliber of SMA connectors and SMB connectors are different. Therefore, they can only be used interchangeably if they are of the same type.

If you want to know more information about the SMA connector of LenoRF, welcome to consult us. Our website is www.rfcnn.com.