SMA Pinout
A small threaded 50-ohm coaxial connector for microwave RF up to ~18 GHz.
Overview
SMA (SubMiniature version A) is a compact threaded coaxial connector widely used for RF and microwave interconnects on antennas, radios, and test gear. It provides a precise 50 ohm path and screws together with a 1/4-36 thread.
Like all coax connectors it has two conductors: a center pin (standard SMA plug is male) carrying the signal and the threaded outer body carrying the shield/ground. Standard SMA works to about 18 GHz.
Pinout
| Pin | Name | Function | Description |
|---|---|---|---|
| Center | Signal | SIGNAL | Center contact carrying the RF signal |
| Shield | Ground / Shield | GND | Threaded outer body, coax shield and ground return |
Notes
- 50 ohm. Standard SMA plug has a male center pin; usable to ~18 GHz.
- Do not confuse with RP-SMA, which reverses the center-contact gender.
Reference: Wikipedia — SMA connector· verified 2026-06-27