What should be noted when purchasing SMA connectors?

Like other connectors, the SMA connector plays a bridge role in the transmission of signals in cables or instruments and has a wide range of applications. Therefore, the varieties and models of SMA connectors are also particularly large, which need to be considered in the purchasing process. Next, we will introduce what should be noted when purchasing SMA connectors.

Here is the content list:

l Interface mechanism types

l Cable assembly methods and cable types

l Material and plating

l Electrical performance

l Insulation resistance

l Flammability

Interface mechanism types

The connection mechanism of the SMA connector is to offer a convenient and fast connection or separation of the coaxial transmission line. When there is not enough space to rotate the connection nut in the use case, a non-twist type connection mechanism should be selected.

Cable assembly methods and cable types

1、The SMA connector has two methods of the cable assembly. The first is to weld the center conductor and combine braided wire, especially suitable for no special installation tools occasions, and to facilitate field maintenance. The second is to weld the center conductor and crimp the braid layer. Due to high efficiency, reliable termination performance, and good consistency, the crimping method has become a common method today. The termination contact of our SMA connector RG174 from LenoRF uses this crimping method.

2、Suitable connectors should be selected according to the characteristics of the various types of cables used, such as flexible cables, semi-rigid cables, wrinkle conductor insulated cables, and blister insulated cables. Generally speaking, cables with thin outer diameters are matched with small connectors. For example, the cable type of our SMA connector RG174 from LenoRF is N/A.

Material and plating

1、The material of the SMA connector's housing and inner conductor is mainly brass, beryllium copper, and tin bronze. Insulator material is mainly tetrafluoroethylene. And the center conductor of the SMA connector is generally coated with silver or gold, and nickel or silver plating on the shell. For example, the body material of our SMA connector RG174 from LenoRF is brass, and the body plating is gold.

2、When the components are connected, the materials and plating used on SMA connectors are different. The conductivity of the corresponding metal will be different, and the resulting contact resistance is also different. For example, the conductivity of gold is certainly the best. But because the price of gold is expensive, we have to consider the plating according to the cost of connector production.

Electrical performance

1、The first is to consider the characteristic impedance. SMA connectors should match the impedance of the transmission system and cable, otherwise, it will lead to degradation of the system performance.

2、Then consider the withstand voltage. The maximum withstands voltage value of SMA connectors should match the withstand voltage requirement for system use. In general, if it is in a broadband application, we need to sacrifice some favorable broadband impedance matching characteristics to obtain the required high voltage rating.

Insulation resistance

Insulation resistance refers to the resistance value of the insulating part of the SMA connector when voltage is applied to the insulating part, resulting in leakage current within or on the surface of the insulating part. It is mainly influenced by the insulation material, temperature, humidity, and damage.

Flammability

Any connector in the work can not be separated from the current, which is the risk of fire. Therefore, the connector is not only required to prevent ignition but also required in the event of ignition and fire, and can be self-extinguishing in a short period. Therefore, we need to choose the flame retardant SMA connectors.

For more information about the SMA connectorof LenoRF, please consult us. The website is www.rfcnn.com.