This application shows how power resistors can be implemented in a circuit. Under normal conditions when the amplifier is perfectly balanced, the resistors are actually never used. The incoming signal is split into two phases – amplified and recombined. This is an effective way of increasing the output power without pushing the signal into an area of high distortion and poor quality. If one of the phases is interrupted by a component failure, then that phase of the signal is reflected back towards the hybrid coupler, not through the remaining phase which would cause distortion.