An RF lens includes a multitude of radiators adapted to transmit radio frequency electromagnetic EM waves whose phases are modulated so as to concentrate the radiated power in a small volume of space in order to power an electronic device positioned in that space. Accordingly, the waves emitted by the radiators are caused to interfere constructively at that space. The multitude of radiators are optionally formed in a one-dimensional or two-dimensional array. The electromagnetic waves radiated by the radiators have the same frequency but variable amplitudes.

An RF lens includes a multitude of radiators adapted to transmit radio frequency electromagnetic EM waves whose phases are modulated so as to concentrate the radiated power in a small volume of space in order to power an electronic device positioned in that space. Accordingly, the waves emitted by the radiators are caused to interfere constructively at that space. The multitude of radiators are optionally formed in a one-dimensional or two-dimensional array. The electromagnetic waves radiated by the radiators have the same frequency but variable amplitudes.

An RF lens includes a multitude of radiators adapted to transmit radio frequency electromagnetic EM waves whose phases are modulated so as to concentrate the radiated power in a small volume of space in order to power an electronic device positioned in that space. Accordingly, the waves emitted by the radiators are caused to interfere constructively at that space. The multitude of radiators are optionally formed in a one-dimensional or two-dimensional array. The electromagnetic waves radiated by the radiators have the same frequency but variable amplitudes.

There is provided mechanisms for precoding over a beam subset. A method is performed by a network node. The method comprises exchanging reference signal information for a set of transmission beams or set of antenna ports with a wireless device. The method comprises acquiring, based on the reference signal information, information regarding which proper subset of transmission beams from the set of transmission beams to use for communication with the wireless device. The method comprises determining precoding weights for the proper subset of transmission beams or antenna ports based on the reference signal information

This application provides implementations related to lenses. In one implementation, a lens comprises a substrate layer and a metal layer, wherein at least one surface of the substrate layer is a concave surface or a convex surface; the metal layer exists on the at least one surface of the substrate layer; the metal layer comprises a metal part and a hollow-out part, and the metal part or the hollow-out part is presented by using a graphics array; the graphics array comprises a plurality of first rings, the first ring comprises a plurality of graphic units, and a larger ring encircles a smaller ring in the plurality of first rings; and at least one of the following are different: size of graphic units comprised in two adjacent first rings, rotation angle of graphic units comprised in two adjacent first rings, or two adjacent first intervals, wherein the first interval is an interval between the two adjacent first rings.

An RF lens includes a multitude of radiators adapted to transmit radio frequency electromagnetic EM waves whose phases are modulated so as to concentrate the radiated power in a small volume of space in order to power an electronic device positioned in that space. Accordingly, the waves emitted by the radiators are caused to interfere constructively at that space. The multitude of radiators are optionally formed in a one-dimensional or two-dimensional array. The electromagnetic waves radiated by the radiators have the same frequency but variable amplitudes.

An RF signal generator wirelessly transferring power to a wireless device includes, in part, a multitude of generating elements generating a multitude of RF signals transmitted by a multitude of antennas, a wireless signal receiver, and a control unit controlling the phases and/or amplitudes of the RF signals in accordance with a signal received by the receiver. The signal received by the receiver includes, in part, information representative of the amount of RF power the first wireless device receives. The RF signal generator further includes, in part, a detector detecting an RF signal caused by scattering or reflection of the RF signal transmitted by the antennas. The control unit further controls the phase and/or amplitude of the RF signals in accordance with the signal detected by the detector.

An RF signal generator wirelessly transferring power to a wireless device includes, in part, a multitude of generating elements generating a multitude of RF signals transmitted by a multitude of antennas, a wireless signal receiver, and a control unit controlling the phases and/or amplitudes of the RF signals in accordance with a signal received by the receiver. The signal received by the receiver includes, in part, information representative of the amount of RF power the first wireless device receives. The RF signal generator further includes, in part, a detector detecting an RF signal caused by scattering or reflection of the RF signal transmitted by the antennas. The control unit further controls the phase and/or amplitude of the RF signals in accordance with the signal detected by the detector.

An RF signal generator wirelessly transferring power to a wireless device includes, in part, a multitude of generating elements generating a multitude of RF signals transmitted by a multitude of antennas, a wireless signal receiver, and a control unit controlling the phases and/or amplitudes of the RF signals in accordance with a signal received by the receiver. The signal received by the receiver includes, in part, information representative of the amount of RF power the first wireless device receives. The RF signal generator further includes, in part, a detector detecting an RF signal caused by scattering or reflection of the RF signal transmitted by the antennas. The control unit further controls the phase and/or amplitude of the RF signals in accordance with the signal detected by the detector.

A wireless power generating unit, includes, in part, a multitude of transmitting elements transmitting a multitude of RF signals to a wireless device, a backscatter RF receiver configured to receive the backscattered RF signal from the wireless device in response to the transmission of the RF signals, and a processor adapted to change the phases of the multitude of RF signals values in accordance with the strength of the received backscattered signal. The phases are changed to maximize the strength of the backscattered signal which may be modulated by varying a resistive load at the wireless device. The modulated backscattered signal may be encoded to carry information. The modulation frequency may be representative of the identity of the wireless device. The information may define the amount of RF power received by the wireless device.