A radio-frequency power receiving device has RF antennas connected to multiple controllable rectifying circuits to produce corresponding DC signals which are combined in a controllable switching network to produce a combined DC output. A control unit determines an amplitude control signal that controls each rectifying circuit and also determines switch control signals that control a switching network. The switching network controllably combines the direct-current signals to combine the multiple corresponding direct-current signals in series, in parallel, or in a combination of series and parallel.