This paper presents a new approach for controlling power consumption in RF devices. The approach is based on the definition of application-dependent performance modes for power hungry RF circuits and a logical control strategy that adjusts the power supply of each circuit to the mode required by the application. The control strategy uses embedded sensors, a recursive parameter identification approach and regression models for performance prediction, while demanding minimum embedded resources for computation. The control strategy is robust with respect to circuit parametric deviations due to the manufacturing process or ageing mechanisms. The strategy is illustrated for the case of an RF LNA using envelope detectors as embedded sensors. Simulation results of the control strategy at the transistor-level illustrate the energy savings that can be obtained for an example application.