Subminiature Version B (SMB) Coaxial Connectors

SMB Coax Connector

Subminiature Version B (SMB) Connectors are a coaxial connector type that has been around for roughly 60 years. SMB connectors are among the snap-on, blind-mate, or push-connect type of coaxial connectors and can be found as either 50 Ohm or 75 Ohm varieties. These connectors are generally specified to operate from DC to 2 GHz, 3 GHz, or 4 GHz, depending on the quality of construction and material selection. SMB connectors are either SMB Jack Connectors or SMB Plug Connectors, where the plug connectors are pressed into the jack connectors until they make a flush connection with the back wall of the jack connector and activate the retention mechanism within the jack. The SMB connector uses the SMB plug as a female and the SMB jack as the male, unlike other coaxial connector and electrical connector standards.

SMB connectors are commonly available as SMB Jack Right Angle Connectors, SMB Jack Straight Connectors, SMB Plug Right Angle Connectors, SMB Plug Straight Connectors. The main advantage of SMB connectors is the ease in which they are mated, though this does sacrifice some rigidity, ruggedness, and performance compared to threaded coaxial connectors, SMB connectors also have relatively low power handling and operating voltage compared to threaded coaxial connectors. This is why SMB connectors are often used in non-critical applications that either require repeated mating, need to be installed by non-experienced technicians/laymen, or within systems where the interconnect is not critical and there are economic/process advantages to rapid and low-profile connector installation.

Though the lack of a threaded retention and mating nut with SMB connectors does sacrifice some mechanical and electrical advantages, the blind-mate ability of SMB results in no special tooling or technique required to successfully mate this connector. Hence, these connectors are readily mated using robotic systems or untrained personnel. Also, SMB connectors are considerably lower profile than threaded coaxial counterparts and don’t require clearance between the ports for a wrench tool that threaded coaxial interconnect require.

These connectors are often used in telecommunications applications for interconnect in base stations, antennas, RF boards, PC/LAN connections, GPS receivers, and other high frequency applications that are cost sensitive and require a smaller connector profile than SMA. Some industrial automation, medical device, instrumentation, controls, radar, broadcast, wireless, military/defense, and aerospace applications employ SMB connectors for various use cases.