The SMA (SubMiniature version A) connector is a semi-precision coaxial RF connector developed in the 1960s. As the smallest connector interface for coaxial cables, it has a screw-type coupling mechanism. The connector has a 50 Ω impedance. The SMA connector is typically rated for mode-free operation from DC to 18 GHz and sometimes more.
The SMA connector comes in various formats, male, female, straight, right-angled, bulkhead fitting, and many more, enabling it to meet most requirements. Its sub-miniature size enables it to be used, even within relatively small items of electronic equipment.