A split ring resonator (10) as a unit cell of a passive element includes a conductor (1) made of a metal and having an annular shape split by a first gap (2) and a second gap (3) different from the first gap (2). A first capacitance generated by the first gap (2) is different from a second capacitance generated by the second gap (3).

An MIMO training method including performing transmission sector sweeping using an initiator including a plurality of transmitting antennas, selecting a set of at least one transmission sector for each of the transmitting antennas using a responder including a plurality of receiving antennas; performing reception sector sweeping using the initiator, selecting a set of at least one reception sector for each of the plurality of receiving antennas using the responder, performing beam combination training using the initiator; and selecting a determined number of sector pairs consisting of a transmission sector and a reception sector from among the selected set of transmission sectors and the selected set of reception sectors using the responder, wherein the transmitting antennas in the selected sector pairs differ from one another, and the receiving antennas in the selected sector pairs differ from one another.

A multi-level antenna array includes a plurality of patch antennas. Each layer of a plurality of layers is separated from other layers by a distance and support a portion of the plurality of patch antennas. Each of a plurality of connectors is associated with one of the plurality of layers for supplying a signal for transmission by the associated layer. A feed network on each of the plurality of layers provides a connection between a connector of the plurality of connectors associated with the layer and the portion of the plurality of patch antennas located on the layer. Each layer of the plurality of layers transmits the signal having a different orthogonal function applied thereto and multiplexes each of the signals having the different orthogonal function applied thereto onto a single transmission beam.

Embodiments of the present disclosure disclose an antenna array applied to an optical phased array, the optical phased array, and a LiDAR. The antenna array includes N phase compensation groups and N antenna groups, where each phase compensation group includes M phase compensation units, and each antenna group includes M antenna units, and where N and M are positive integers. An input end of a phase compensation unit in the phase compensation group is configured to receive an optical signal. An output end is connected to an antenna unit in the antenna group, is configured to transmit the received optical signal to the antenna unit, and performs phase compensation on the optical signal based on a phase shift caused by the antenna unit. The antenna unit is configured to transmit the optical signal.

A system includes a phased array antenna. The phased array antenna includes a rear panel that has: a first array of phase shift elements; and a second array of rear antenna elements. The phased array antenna also includes a front panel that has a third array of front antenna elements. Each of the front antenna elements is electrically coupled to a corresponding one of the rear antenna elements through one of the phase shift elements. When the second array of rear antenna elements receives a radio signal from a base station and the first array of phase shift elements receives an optical control beam from the base station, the third array of antenna elements radiates an output radio signal in a direction indicated by the optical control beam.

An electronic device may include a fully-connected photonic phased antenna array having a set of antennas, each with an antenna resonating element coupled to a set of photodiodes. Optical modulators may receive different wireless data streams and may generate modulated signals. Optical paths may provide the modulated signals generated by each modulator to a different photodiode in each antenna. Sets of optical phase shifters may apply different sets of phase shifts for each of the modulated signals. Optical paths may provide the phase shifted signals to the photodiodes in the antennas. The photodiodes may produce currents that are superposed on the antenna resonating elements. Each antenna may be used to concurrently convey all of the wireless data streams. The phase shifts may configure the array to transmit signals that include the wireless data streams within different respective signal beams.

An MIMO training method including performing transmission sector sweeping using an initiator including a plurality of transmitting antennas, selecting a set of at least one transmission sector for each of the transmitting antennas using a responder including a plurality of receiving antennas; performing reception sector sweeping using the initiator, selecting a set of at least one reception sector for each of the plurality of receiving antennas using the responder, performing beam combination training using the initiator; and selecting a determined number of sector pairs consisting of a transmission sector and a reception sector from among the selected set of transmission sectors and the selected set of reception sectors using the responder, wherein the transmitting antennas in the selected sector pairs differ from one another, and the receiving antennas in the selected sector pairs differ from one another.

A first region of a reflection mirror including a center point of the paraboloid of revolution is formed of a conductor. A second region, which is an outer peripheral side of the first region, of the reflection mirror is a region where a plurality of reflection elements, which are conductor patterns, is arranged on a dielectric body overlaid on a base plate conductor. An arrangement pitch of the plurality of reflection elements corresponds to a wavelength of a radio wave in the second frequency band.

A unit cell can be used for a metasurface, metamaterial, or beamforming antenna. The unit cell includes a metal layer attached to a substrate. The metal layer defines an iris opening for the unit cell. One or more tunable capacitance devices are positioned within or across the iris opening. Each tunable capacitance device is to tune resonance frequency of the unit cell. Mass transfer technologies or self-assembly processes may be used to position the tunable capacitance devices.

An antenna system may include a source antenna, a frequency selective surface (FSS), and a second antenna or a fluidic channel associated with a housing. In both examples, the FSS has a first side and a second side opposite from the first side. The first side includes horizontally oriented unit cells positioned as multiple columns of unit cells. The first side of the FSS faces the source antenna and is separated from the source antenna by a defined distance. The housing is positioned on the second side of the FSS. In the latter example, the fluidic channel of the housing includes one of air or deionized water. The fluidic channel is positioned on a portion of the second side of the FSS that is opposite to a subset of the horizontally oriented unit cells on the first side of the FSS.