Directional Couplers: How do you specify them?

Directional couplers are an integral poart of any RF system. They are used to sample a portion of an incoming RF signal without affecting the mainline losses signifcantly as opposed to power splitters.

Some of the uses of a directional coupler are:

• monitoring power levels
• input power protection
• automatic gain control
• automatic power level control
• system self-test
• system calibration
• phase locked loops on synthesizers