Aspects of this disclosure relate to detecting power associated with an individual carrier of a carrier aggregated signal. In an embodiment, a carrier aggregation system includes radio frequency (RF) sources, a transmission output, and a directional coupler. The RF sources, such as power amplifiers, can each be associated with a separate carrier. The transmission output can provide a carrier aggregated signal that includes an aggregation of the separate carriers associated with the RF sources. The directional coupler can provide an indication of RF power of one of the separate carriers.