A transmitter, according to some implementations, includes: at least two antennas configured to transmit at least two radio frequency power signals； a power transmission module connected to the at least two antennas, the power transmission module configured to generate the at least two radio frequency power signals； and a power transmitter control module connected to the power transmission module, the power transmitter control module configured to control a first phase and a first amplitude of a first of the at least two radio frequency power signals and a second phase and a second amplitude of a second of the at least two radio frequency power signals to concurrently provide respective summations of the first and second radio frequency power signals at a first wireless power receiver of a first electronic device and at a second wireless power receiver of a second electronic device via constructive interference.
