SMB connector is one kind of coaxial RF connectors which have smaller size than SMA connector and were designed in 1960’s with snap-on coupling. The snap-on design permits rapid connection and disconnection in limited spaces.

SMB connectors are available either in 50ohm or 75ohm impedance. 50ohm SMB connectors usually was specified up to 4GHz, and 75ohm SMB connectors are specified for only 2GHz.

SMB connectors are designed originally with female contact in male body or male contact in female body. These connectors are popularly used in telecommunication and automotive.

Mechanical Feature:
SMB male

Snap-on coupling
Six slots radically spaced outer contact inside shell
Shell is fixed and can’t be rotated.
Female center contact
Insulator surrounds female center contact wholly for 50ohm SMC male
An air gap between female center contact and outer contact for 75ohm SMB male
SMB female

Snap-on coupling
A trough for mating captive after a smooth area of dia. 3.7mm, 3.0mm length from mating end
Male center contact
Insulator nestles up throughout against outer contact. An air gap between insulator and male center contact for 50ohm SMB female
Reducing insulator amount. An air gap between male center contact and outer contact for 75ohm SMB connector.