Combiner

n. someone or something that combines

A diplexer is a device that combines radio frequency inputs from two or more radio transmitters into a single output, or, when used in the opposite direction, divides a single RF input into two or more outputs based on frequency using bandpass filters. Depending on how it is used, a diplexer may be called a combiner or splitter. The device is referred to as a duplexer in land mobile radio, where a receiver and transmitter are sometimes combined onto the same antenna. Though the basic goal is the same in all diplexers, there are massive variations in scale depending upon the application.
See more at Wikipedia.org...

v. combine, contrive; work out, scheme, devise

(n.)
One who, or that which, combines.
  

See maximal-ratio combiner.