Embodiments of the disclosure include a Radio Detection and Ranging (Radar) system with reduced transmitter antenna and receiver antenna mutual coupling. The radar system includes a transmitter antenna disposed on a first side of the dielectric substrate and a receiver antenna disposed on the same side of the dielectric substrate. The radiation boundaries of the transmitter antenna and the receiver antenna are substantially parallel to a line connecting centroids of the transmitter antenna and the receiver antenna. The radar system also includes a ground plane disposed on a second side of the dielectric substrate, opposite to the first side, operatively connected to the transmitter antenna and the receiver antenna through probes. The ground plane comprises at least one groove, separating vertical projections of the transmitter antenna and the receiver antenna on the ground plane.

An orthopedic system configured for use in a pre-operative, intra-operative, and post-operative assessment. The orthopedic system comprises a first screw, a second screw, a first device, a second device, and a computer. The first device and the second device are respectively coupled to a first bone and a second bone of a musculoskeletal system. The first and second devices each include electronic circuitry, one or more sensors, and an IMU. A bracket, wrap, or sleeve can be used to hold the first and second devices to the musculoskeletal system. The first and second devices are configured to send measurement data to a computer. The first and second devices each have an antenna system. Electronic circuitry in the first or second devices are configured to harvest energy from a received radio frequency signal to recharge a battery to maintain operation.

A wireless charging transmission apparatus by using 3D polyhedral magnetic resonance based on multi-antenna switching includes a magnetic resonance wireless energy transmitting module, a plurality of magnetic resonance transmitting antennas, a plurality of receiving antennas, and a magnetic resonance wireless energy receiving module that are connected in sequence. The magnetic resonance wireless energy transmitting module is configured to convert DC power into RF energy and control an operation mode. The magnetic resonance transmitting antennas are configured to convert the RF energy into a spatially distributed reactive field. The receiving antennas are configured to convert the reactive field into the RF energy. The magnetic resonance wireless energy receiving module is configured to convert the RF energy into DC power and charge or power a load. When one of the transmitting antennas is used as a main transmitting antenna, the rest transmitting antennas are used as relay coupling antennas.

A long-range wireless power transfer system 100 is disclosed. The system 100 comprises at least a transmitting antenna 110 that is configured to receive electric power from a power source as an input, convert the input electric power into electromagnetic energy, and radiate the electromagnetic energy into free space as a directional beam that is a collimated or substantially collimated beam. The rectifying antenna 130 is positioned or configured to be positioned at a distance from the transmitting antenna 110. The rectifying antenna 130 is configured to receive the directional beam and convert the electromagnetic energy into electricity. In certain embodiments, the system 100 utilise one or more phase correcting devices 120, 122 to maintain the directional beam as the collimated beam and to increase a range to which the directional beam is maintained as the collimated or substantially collimated beam.

A radio frequency identification (RFID) antenna is disclosed. The RFID antenna may include: a substrate; a radiator disposed on the substrate, the radiator comprising a first electrical conductor and a second electrical conductor that perpendicularly intersect a straight edge of the radiator, the first electrical conductor and the second electrical conductor being symmetrical to each other with respect to a central point of the radiator; a loop disposed on the substrate; and a stub disposed on the substrate between the loop and the central point of the radiator.

An antenna element includes a dielectric substrate, a radiation electrode, a first ground electrode, a second ground electrode, and a via conductor that connects the first ground electrode and the second ground electrode to each other. The dielectric substrate includes a flat-plate-shaped first part and a second part that is thinner than the first part. The radiation electrode and the first ground electrode are arranged on or in the first part so as to face each other in the thickness direction of the first part. The second ground electrode is spaced apart from the radiation electrode. The second ground electrode is arranged on or in the second part so as to not face the radiation electrode in the thickness direction of the second part. The radiation electrode is capacitively coupled to the second ground electrode and the via conductor.

An exemplary embodiment of the present disclosure provides a backscattering RFID system comprising: a combined oscillator and reflection amplifier circuit comprising a first tunnel diode having an anode and a cathode; and a biasing circuit in communication with the anode and configured to bias the first tunnel diode in a negative differential resistance region; wherein the combined oscillator and reflection amplifier circuit is configured to modulate a RF interrogation signal to produce a backscatter signal.

An element includes a loop antenna configured to include first and second metal lines on a surface of a substrate on or from which terahertz waves are incident or emitted, and a rectifying element or an oscillation element electrically connected to the first and second metal lines. The element has a facing section at which a first surface of a first end not connected to the rectifying element or the oscillation element at an end of the first metal line faces a second surface of a second end not connected to the rectifying element or the oscillation element at an end of the second metal line, a direction in which the first surface faces the second surface is a direction in which the first end extends and is a direction intersecting a direction in which the second end extends.

An electronic device includes an antenna module configured to perform millimeter wave communication with an external radio frequency device; a radio frequency communication module configured to receive a millimeter wave communication signal transmitted by the external radio frequency device forwarded by the antenna module when the radio frequency communication module is connected with the antenna module; a radio frequency charging module configured to receive a millimeter wave charging signal transmitted by the external radio frequency device forwarded by the antenna module when the radio frequency charging module is electrically connected to the antenna module, and rectify the millimeter wave charging signal into a direct-current signal output; and a processing module electrically connected to the antenna module, the radio frequency communication module, and the radio frequency charging module, respectively to control the electrical connection between the antenna module and the radio frequency communication module, and/or the radio frequency charging module.

An electrically conductive material configured having at least one opening of various unlimited geometries extending through its thickness is provided. The opening is designed to modify eddy currents that form within the surface of the material from interaction with magnetic fields that allow for wireless energy transfer therethrough. The opening may be configured as a cut-out, a slit or combination thereof that extends through the thickness of the electrically conductive material. The electrically conductive material is configured with the cut-out and/or slit pattern positioned adjacent to an antenna configured to receive or transmit electrical energy wirelessly through near-field magnetic coupling (NEMC). A magnetic field shielding material, such as a ferrite, may also be positioned adjacent to the antenna. Such magnetic shielding materials may be used to strategically block eddy currents from electrical components and circuitry located within a device.