SIGNAL POWER MANAGEMENT CIRCUITS AND SMART CARDS INCLUDING THE SAME

Signal power management circuits (400) and smart cards (1000) including the same are provided. For example, a signal power management circuit (400) comprises a rectifier (420) that is configured to rectify a received radio frequency signal and output a first rectified voltage (VDDU PRE), a first regulator (430) that is configured to maintain the first rectified voltage at a predetermined first voltage level, and a second regulator (440) that is configured to receive an output of the first regulator and maintain a second rectified voltage (VDDU) different from the first rectified voltage at a predetermined second voltage level. A signal detector (470) of the signal power management circuit is configured to receive the first rectified voltage and the second rectified voltage and detect a signal component of the received radio frequency signal on the basis of a difference between the first voltage level of the first rectified voltage and the second voltage level of the second rectified voltage.