Connectors - QMA SMB SMC

QMA / SMB / SMC Connectors - This collection contains QMA, SMB and SMC RF connectors. Although all three are relatively small RF connector families, they use different mating systems and should not be confused with one another.

QMA Connector - QMA is a quick-lock RF connector developed as an alternative to the threaded coupling used by SMA connectors. The QMA uses a snap-on/quick-lock coupling that allows fast connection and disconnection. The connector can rotate after mating, which can make cable routing and installation easier. QMA connectors are normally 50 Ohm and are commonly used in wireless, communications and other RF applications.

SMB Connector - SMB stands for SubMiniature Version B. It is a small snap-on RF connector that does not require a threaded coupling nut. SMB connectors are available in both 50 Ohm and 75 Ohm versions, so the impedance should be verified when selecting a connector.

SMB terminology can be confusing. On a standard SMB interface, the SMB Plug has a female center contact (socket or basket), while the SMB Jack has a male center contact (pin).

SMC Connector - SMC stands for SubMiniature Version C. Unlike the snap-on SMB connector, SMC uses a threaded coupling to provide a secure connection in a small RF connector. SMC connectors are commonly 50 Ohm and are used in communications, instrumentation and other compact RF applications.

Important: Plug and Jack describe the mating configuration of a connector, while Pin and Socket describe the center RF contact. Do not assume that the relationship between Plug/Jack and Pin/Socket is identical across different RF connector families. Always verify the connector family, mating interface and center contact when selecting a connector.

HEX Crimp Die Sizes* for FERRULES for common RF Cables: