SMP barrel coupler — 40 GHz, female on both ends
The Molex 0734066420 is a straight SMP jack-to-jack adapter from the 73406 series, designed as a same-series barrel coupler. Both ends present an SMP jack with a female center socket, so it mates two SMP plug connectors end-to-end. The adapter is specified for 50 Ohm systems and is rated to 40 GHz, covering the full DC-to-millimeter-wave band that SMP interfaces are built for. The body and center contact are machined from beryllium copper, with gold plating on both surfaces. Beryllium copper gives the snap-on fingers the spring memory to hold repeat mates without taking a set; the gold finish keeps contact resistance low and stable across the 40 GHz range. Mounting is free-hanging (in-line), meaning this adapter sits between two cable assemblies or between a cable and a board-mounted SMP jack — there are no panel-mount flanges or bulkhead threads. The snap-on fastening on both ends matches the standard SMP interface, so no special tooling is needed for installation; the adapter pushes onto the mating plugs and locks with an audible click.
40 GHz — what the frequency rating means for the signal path
The 40 GHz max frequency is the adapter's defining spec.