VPX, also known as VITA 46, is a computer bus standard that allows systems based on the VMEbus standard to operate over high-speed switching fabric network topologies. Designed especially for defense applications, VPX also features a robust high-speed connector with minimal insertion loss and low crosstalk.
VPX PCBs are designed to be plugged into a standard chassis which in turn is mounted in a standard 19-inch rack. There are two VPX form factors, 3U and 6U, where 1U is a rack unit of 1.75 in (44.45 mm) and all cards must be 33.35 mm (1.313 in) shorter than the enclosure. 3U VPX dimensions are thus 100 mm height in a 5.25 in (133.35 mm) enclosure and 6U VPX dimensions are 233.35 mm height in a 10.5 in (266.70 mm) high enclosure.
Advantages of VPX for UAV, drone and robotics designs include speeds of up to 10.3 Gbit/sec and high I/O capacity. 3U VPX is especially suited for SWaP-constraint platforms with applications such as SIGINT (signal intelligence) and electronic warfare.