An apparatus includes a first directional coupler, a second directional coupler, a first detector, and a second detector. A through port of the first directional coupler is coupled to a through port of the second directional coupler. An isolated port of the first directional coupler is coupled to an isolated port of the second directional coupler. A coupled port of the first directional coupler is coupled to the first detector. A coupled port of the second directional coupler is coupled to the second detector. A detected power signal is generated by combining an output of the first detector and an output of the second detector.