Samsung patents circuit that automatically tunes power efficiency

1. An electronic device comprising: a matching circuit comprising a plurality of capacitors and a plurality of switches, having different matching impedance values according to connection states of the plurality of switches, and configured to output a matching power signal by impedance matching an input power signal; a power conversion circuit configured to convert the matching power signal in an alternating current (AC) form into an output power signal in a direct current (DC) form; and a controller configured to set the matching impedance value of the matching circuit by transmitting a switching signal to the plurality of switches, wherein the switching signal sets the connection state of the plurality of switches, and wherein the controller is further configured to: receive the output power signal from the power conversion circuit, while increasing the matching impedance value by a first adjustment value, select an optimal matching impedance value based on a plurality of output power signals that are received from the power conversion circuit; set, as the matching impedance value, an impedance value that is greater than a matching impedance value corresponding to an output power signal having a maximum voltage value among the plurality of output power signals by a second adjustment value, and receive an additional output power signal from the power conversion circuit in response to a voltage value of the received output power signal being less than a voltage value of a previously received output power signal; select, as the optimal matching impedance value, a matching impedance value corresponding to a greater value of the maximum voltage value of the plurality of output power signals and a voltage value of the additional output power signal, wherein the second adjustment value is less than the first adjustment value; and set the optimal matching impedance value as the matching impedance value.