16 results about "Reradiation" patented technology

The invention discloses a metasurface array antenna housing, belongs to the technical field of electromagnetic wave regulation and control, and solves the problem of how to improve the transmittance and absorptivity of a metasurface to electromagnetic waves. Electromagnetic waves with different frequencies resonate on the first metasurface wave-absorbing layer and the second metasurface wave-absorbing layer respectively, so that the electromagnetic waves are absorbed by the lumped resistor. And the metasurface wave-transmitting layer re-radiates electromagnetic waves of a communication frequency band to enable the electromagnetic waves to penetrate through the metasurface unit, and meanwhile, the surface of the metasurface wave-transmitting layer can serve as a metal floor of the first metasurface wave-absorbing layer and the second metasurface wave-absorbing layer due to copper coating. The antenna can be widely used in the scenes of radar stealth, communication antenna integration, electromagnetic compatibility, wireless energy transmission and the like, and has a good application prospect.

A radar apparatus in an aspect of the present disclosure includes: a radar module including a transmitting antenna that transmits a transmission signal; and a re-radiator including a re-radiating element that re-radiates the transmission signal.

Provided is a high frequency signal receiving unit that receives a first high frequency signal and that generates a first intermediate frequency signal. A packet generating unit generates a packet on the basis of the first high frequency signal. A packet output unit outputs the generated packet to a communication path. A packet receiving unit receives the packet via the communication path. A packet interpreting unit performs synchronization processing for the packet and generates a second intermediate frequency signal. A high frequency signal transmitting unit converts the second intermediate frequency signal into a second high frequency signal and transmits the second high frequency signal. A wireless receiver receives the second high frequency signal and performs positioning or time synchronization on the basis of the second high frequency signal.

The application discloses a low-power-consumption common-gain adjustable metasurface based on nonlinear negative resistance, which comprises a low-power-consumption metasurface unit and a backscattering amplifier connected in series with the low-power-consumption metasurface unit; the low-power-consumption metasurface unit comprises, from top to bottom, an upper copper sheet, an upper dielectric, a metal ground, a lower dielectric and a bottom RLC switching circuit layer; wherein the upper copper sheet is connected with the bottom RLC switching circuit through a through hole; the bottom RLC switching circuit layer comprises a plurality of radio frequency switches and LC circuits or resistors embedded between the radio frequency switches; the backscattering amplifier comprises a matching circuit, the matching circuit is connected with an amplifying circuit through a direct-current isolation part, and the amplifying circuit is connected with a bias circuit through a cross isolation part. After an electromagnetic signal is input into the amplifying circuit through the bottom RLC switching circuit, the LC circuit or the resistor is selected through the radio frequency switch, the electromagnetic signal is amplified, and then the electromagnetic signal is reflected, the LC circuit or the resistor is selected through the radio frequency switch, the electromagnetic signal is transmitted to the upper copper sheet, and then the electromagnetic signal is radiated to the free space.

The invention provides a radar device and a radar system, which can monitor a plurality of monitoring ranges by one radar device. A radar device according to one embodiment of the present disclosure is provided with: a radar module that radiates a transmission signal; and a re-radiating unit that re-radiates the transmission signal by transmission and / or reflection.

A harmonic radar system for detecting a battery may include a signal generator for generating one or more transmit radio frequency (RF) signals, one or more low-pass filters for removing harmonics from the transmit RF signals, a transmitting antenna for sending the transmit RF signals into an environment, a receiving antenna for receiving signals reflected or re-radiated by the battery in the environment in response to the transmit RF signals, one or more high-pass filters for filtering the received signals, and a spectrum analyzer for identifying a harmonic frequency of the transmit RF signals in the filtered signals.

The invention discloses a gain millimeter wave programmable metasurface regulated and controlled by an MOS switch, and belongs to the field of novel artificial electromagnetic materials. According to the structure, a reflective metasurface unit integrating the power amplifier and the MOS switch chip is realized, x-polarized wave receiving is realized in the high-isolation dual-polarized rectangular patch antenna unit structure, y-polarized wave re-radiation is realized after micro-strip transmission and amplification, y-polarized reflection phase can be changed by adjusting on-off of the MOS switch chip, and the antenna has the advantages of high-isolation dual-polarized rectangular patch antenna unit structure, high-isolation dual-polarized rectangular patch antenna unit structure and high-isolation dual-polarized rectangular patch antenna unit structure. The metasurface array has a very good 1bit effect while ensuring active amplification of signals, so that coding state switching of the metasurface units and far-field beam regulation and control of the metasurface array are realized. The surface is a millimeter wave artificial electromagnetic surface with an active amplification function, is expected to solve the problems of path loss and reflection loss of a current reflective metasurface and the problem of radio frequency signal leakage caused by a programmable metasurface bias circuit, and has important potential application in the fields of intelligent communication, imaging, computing technology and the like.

The present application relates to the technical field of electromagnetic shielding device, and proposes an electromagnetic shielding structure for keyboard, a manufacturing method thereof and a keyboard. The structure is arranged on the inner surface of the upper cover / lower cover of the keyboard or the surface of the insulating cover layer on the printed circuit board, and mainly comprises: a continuous reflection layer extending along a target area and connected to the ground wire of the keyboard through the peripheral ground wire; an absorption layer arranged on the reflection layer, a patterned opening is formed between the absorption layer and the reflection layer, and the depth is limited between the two layers so that the reflection layer remains electrically continuous below the patterned opening; and a protective layer covering the absorption layer, filling the patterned opening and being in contact with the reflection layer. Therefore, the transmission and re-radiation in the target frequency band can be reduced, the cavity and slot resonance can be suppressed, and the backlight channel avoidance and thinning can be considered.

The invention relates to the technical field of disaster prevention and reduction, and discloses an underground structure nondestructive testing method and system for earthquake prevention, and the method comprises the steps: applying a broadband low-frequency transient air pressure excitation signal to the ground surface; utilizing the broadband low-frequency transient air pressure excitation signal to propagate downwards through a rock-soil medium; a high-sensitivity air pressure micro-fluctuation sensor array arranged on the earth surface is adopted to collect secondary air pressure fluctuation signals which are responded by the gas-solid coupling resonance and then radiated to the earth surface in real time; the collected secondary air pressure fluctuation signals are preprocessed, and low-frequency pneumatic resonance characteristics are extracted; according to the three-dimensional distribution of the pneumatic resonance intensity, determining a damaged area with local void or micro-crack of the underground structure, and achieving nondestructive testing for earthquake prevention. According to the method, through the mechanism of earth surface broadband low-frequency transient air pressure excitation and gas-solid coupling resonance response re-radiation, complete nondestructive testing of the deep underground structure is achieved, and damage imaging can be completed without drilling or excavation.

The invention provides an adjacent avoidance effect risk analysis method and system for a noise sensitive area, and the method comprises the steps: obtaining a noise source sound power frequency spectrum and a three-dimensional scene model containing a sensitive area and an obstacle, and generating an initial sound ray set carrying energy, phase and frequency; a sound ray path is tracked in the 3D model, and phase disturbance and amplitude fluctuation caused by atmospheric turbulence are calculated; reflection, diffuse scattering, transmission and vibration re-radiation generated by the action of sound rays and the surface of an obstacle; the method comprises the following steps of: arranging a virtual receiver array in a noise sensitive area according to a diffraction effect when a sound ray arrives at the edge, and reconstructing a time domain sound pressure signal of each receiving point by performing coherent superposition on complex sound pressure reaching the sound ray; psychoacoustic indexes such as loudness are calculated on the basis of the signals and fused into a comprehensive risk index representing the neighbor effect through a preset weighting model.

The invention provides a radar device and a vehicle, which can improve the calculation precision of the position of a target object. A radar device according to one embodiment of the present disclosure is provided with: a radar module having a transmission antenna for transmitting a transmission signal; and a re-radiating unit having a re-radiating element that re-radiates the transmission signal.

The invention is notably directed to an optical sensing device (1) having a layer structure comprising a cavity (40) and a membrane (11) spanning the cavity (40). The membrane (11) includes an aperture (30) to the cavity (40). The device further comprises a plasmonic antenna comprising a pair of opposite antenna elements (17, 17a) patterned on the membrane (11) on opposite lateral sides of the aperture (30). A gap (g) is accordingly defined between the opposite antenna elements, on top of the aperture. This defines a molecular passage extending from the cavity (40), through the aperture (30) and the gap. Interestingly, the device also includes a reflector (35), which is arranged below the aperture. The reflector (35) is configured to reflect electromagnetic radiation onto the gap upon irradiating the plasmonic antenna from a side of the membrane opposite the reflector (35) and focus the reflected electromagnetic radiation onto the gap. The invention is further directed to related devices, apparatuses, and methods for optically sensing analytes, e.g., based on surface-enhanced Raman spectroscopy techniques. The proposed design makes it possible to improve the illumination and photon collection efficiency. The reflection of incident light by the reflector increases the electromagnetic field enhancement in the hot spot region between the antenna elements. Moreover, the reflector collects the photons (e.g., Raman photons) radiated from the molecule and reradiates those photons, ideally into a collimated, parallel beam, which improves the measurement efficiency.

To provide a radar device and a radar system capable of monitoring a plurality of monitoring ranges by one radar device.SOLUTION: A radar device according to an aspect of the present disclosure includes a radar module that radiates a transmission signal, and a re-radiator that re-radiates the transmission signal by at least one of transmission and reflection.SELECTED DRAWING: Figure 1A

An electromagnetic time-reversal beamforming system is provided that can enhance signal integrity, robustness, and real-time adaptability in inter-vehicle communication networks. [Solution] The electromagnetic time-reversal beamforming system of the present invention comprises a rigid support frame (202) carrying spatially distributed antenna array elements, a radio frequency front-end compartment (206), a signal conditioning housing (210), a time-reversal processing unit (214), and a re-radiation subsystem (216).

The invention relates to the technical field of electromagnetic shielding devices, and provides an electromagnetic shielding structure for a keyboard, a manufacturing method of the electromagnetic shielding structure and the keyboard. The structure is arranged on the inner surface of an upper cover / lower cover of a keyboard or covers the surface of an insulating covering layer on a printed circuit board, and mainly comprises an electrically continuous reflecting layer which extends along a target area and is conducted with a keyboard ground wire through a peripheral grounding wire; the absorbing layer is arranged on the reflecting layer, a patterned opening is formed in the absorbing layer and the reflecting layer, and the depth of the patterned opening is limited between the two layers, so that the reflecting layer is kept electrically continuous below the patterned opening; and a protective layer covering the absorbing layer, filling the patterned opening and contacting the reflective layer. Therefore, transmission and re-radiation can be reduced in the target frequency band, resonance of the cavity and the gap is suppressed, and backlight channel avoidance and thinning are both considered.

A radio base station and a radio terminal perform radio communication based on a TDD scheme. A slot configuration includes allocation of a downlink period and an uplink period to the radio terminal. The relay reflects a signal transmitted from the radio base station or the radio terminal or receives and reradiates the signal to form a transmission path between the radio base station and the radio terminal. A relay characteristic includes a parameter determining a coverage area in which the transmission path is formed. A downlink relay characteristic during the downlink period and an uplink relay characteristic during the uplink period are not common but determined separately. Then, the relay characteristic during the downlink period is set to the downlink relay characteristic, and the relay characteristic during the uplink period is set to the uplink relay characteristic. In other words, the relay characteristic is switched between downlink communication and uplink communication.