Methods, systems, and devices are described for improving a performance of a waveguide device. A waveguide device that includes a common port and divided ports may also include a sidewall feature that extends across a first set of opposing sidewalls and a second set of opposing sidewalls of the waveguide device. The sidewall feature may have a same shape on each of the first set of opposing sidewalls and a second set of opposing sidewalls. In some cases, the sidewall feature is positioned outside a divided waveguide section of the waveguide device. The position of the sidewall feature may be determined based on an impedance matching metric between the common port and the divided ports, an isolation metric between the divided ports, or both.

Disclosed is a shaped horn in conjunction with a dielectric tube for enhanced aperture directivity that can achieve a near optimum efficiency. The shaped horn provides additional mode control to provide an improved off-axis cross-polarization response. The horn shape can be individually optimized for isolated horns or for horns in a feed array. The feed array environment can produce results that lead to a different optimized shape than the isolated horn. Lower off axis cross-polarization can result in improved efficiency and susceptibility to interference.

A combiner network is provided. A combiner network may include a corporate combiner. The corporate combiner may include a first plurality of radiation elements. The corporate combiner may include a first H-plane combiner connected to the first plurality of radiation elements and connected by a U-bend to a first E-plane combiner. The corporate combiner may include a second H-plane combiner connected to the first E-plane combiner. The corporate combiner may further include a first port. A plurality of corporate combiners may be assembled together as a combiner network.

A system including an aircraft. A phased array may be configured to transmit electromagnetic (EM) energy toward rotor blades and receive EM energy in a direction from the rotor blades. A processor may be configured to: determine or obtain rotor blade information; determine or obtain aircraft information; based on the rotor blade information and the aircraft information, determine (a) a time to transmit EM energy or receive EM energy and (b) an angle to transmit EM energy or receive EM energy; and based on the rotor blade information and the aircraft information, control the phased array to adjust a beam pointing angle and to transmit EM energy for a duration at the beam pointing angle. The phased array may be configured to transmit EM energy for the duration at the beam pointing angle, wherein the transmitted EM energy is configured to reflect off a rotor blade toward a target.

In an exemplary embodiment, a phased array antenna comprises multiple subcircuits in communication with multiple radiating elements. The radio frequency signals are independently adjusted for both polarization control and beam steering. In a receive embodiment, multiple RF signals of various polarizations are received and combined into at least one receive beam output. In a transmit embodiment, at least one transmit beam input is divided and transmitted through multiple radiating elements, with the transmitted beams having various polarizations. In an exemplary embodiment, the phased array antenna provides multi-beam formation over multiple operating frequency bands. The wideband nature of the active components allows for operation over multiple frequency bands simultaneously.

The technology described herein relates to polarization adaptive wireless power transmission systems. In an implementation, a wireless power transmission system is described. The wireless power transmission system includes an antenna array and control circuitry operatively coupled to the antenna array. The control circuitry is configured to determine polarization information of a beacon signal received from a client device at multiple antennas of the antenna array. The beacon signal is transmitted by a client device in a wireless power delivery environment. The control circuitry is further configured to configure polarization information associated with each of the multiple antennas to match the polarization information determined at respective antennas of the multiple antennas. The present technology enables different wireless power receiver clients to have different polarizations. The wireless power transmission system can efficiently send power to the client devices by matching their polarization.

A multi-frequency folded lens antenna structure includes a stack, and the stack includes a polarization-dependent trans-reflector, a dielectric gap, and a multi-frequency twist-reflector; wherein the polarization-dependent trans-reflector is configured to transmit electromagnetic radiation of a first polarization incident from within the stack out of the stack and to reflect electromagnetic radiation of a second, different polarization incident within the stack towards the multi-frequency twist-reflector, and the multi-frequency twist-reflector is configured to selectively change a polarization of the reflected electromagnetic radiation from the second polarization to substantially the first polarization and to direct the electromagnetic radiation of substantially the first polarization, within the stack, towards the polarization-dependent trans-reflector for at least partial transmission out of the stack, wherein the multi-frequency twist-reflector is configured to selectively change the polarization for at least a first frequency band and for at least a second frequency band, non-contiguous to the first frequency band.

A visible light band reflection metasurface device and a reflected light wavelength modulation method. The device successively includes, from top to bottom, a metal metasurface layer with periodically arranged antenna units, a modulation layer formed by an electro-optic material, a metal reflection layer and a substrate layer; the antenna unit period is less than the incident wavelength, and the thickness is greater than the skin depth of metal and less than 100 nm; the thickness of the modulation layer is less than the wavelength of the incident light; and the thickness of the metal reflection layer is greater than the skin depth of metal and less than the wavelength of the incident light; and an external voltage source can modulate the color of the reflected light, and can achieve voltage modulation of the color of reflected light in the visible light band.

A visible light band reflection metasurface device and a reflected light wavelength modulation method. The device successively includes, from top to bottom, a metal metasurface layer with periodically arranged antenna units, a modulation layer formed by an electro-optic material, a metal reflection layer and a substrate layer; the antenna unit period is less than the incident wavelength, and the thickness is greater than the skin depth of metal and less than 100 nm; the thickness of the modulation layer is less than the wavelength of the incident light; and the thickness of the metal reflection layer is greater than the skin depth of metal and less than the wavelength of the incident light; and an external voltage source can modulate the color of the reflected light, and can achieve voltage modulation of the color of reflected light in the visible light band.

A radio frequency identification (RFID) system includes an RFID interrogator configured for generating an RFID signal, wherein a channel frequency of the RFID signal changes over time; at least one patch antenna; and at least one feed line configured for feeding the signal to the corresponding at least one patch antenna. In another exemplary embodiment, an RFID interrogator configured for generating an RID signal, wherein a channel frequency of the RFID signal changes over time; at least one transmission line; and a diplexer coupling the RFID interrogator and the transmission lines and configured for distributing the RFID signal to each of the antennas or transmission lines, respectively, depending on the channel frequency of the RFID signal generated. The antennas or transmission lines are configured to transmit an electromagnetic wave in response to and at the channel frequency of the RFID signal distributed thereto.