Abstract: The example non-limiting technology herein provides a Synthetic Aperture Radar (SAR) solution on board a micro-satellite that provides global revisit within 1 month; a cost below US$ 10 million; and satellite mass lower than 100 kg. One solution uses an inflatable Cassegrain type antenna with a phased beam steering array in the 1.2 GHz band.

Abstract: The present disclosure relates to a transmission apparatus, including at least one first RF signal connection for an RF signal having a first phase, a ring coupler having a plurality of antenna connections for coupling a plurality of antennas in the first RF signal connection, wherein the ring coupler is configured to cause, at each of different antenna connections of the ring coupler, a constructive superposition of components of the RF signal that propagate from the first RF signal connection to the respective antenna connections in different directions in the ring coupler, wherein RF signals having different phases are obtained at the different antenna connections.

Abstract: Systems and methods to perform object surface estimation using a radar system involve receiving reflected signals resulting from reflection of transmit signals by an object. The method includes processing the reflected signals to obtain an image. The image indicates an intensity associated with at least one set of angle values and a set of range values. The method also includes processing the image to provide the object surface estimation. The object surface estimation indicates a subset of the at least one set of angle values and associated ranges within the set of range values.

Abstract: Disclosed are a method and apparatus for SAR image data enhancement, and a storage medium. The method includes: processing an SAR target image by electromagnetic simulation to acquire an SAR electromagnetic simulation image; and processing the SAR electromagnetic simulation image and the SAR target image by a generative adversarial network to obtain a set of virtual samples of the SAR target image.

Abstract: An ultra-wideband radar transceiver and an operating method thereof are provided. The ultra-wideband radar transceiver includes a receiving module. The receiving module includes an I/Q signal generator, a first sensing circuit and a second sensing circuit. The I/Q signal generator receives M consecutive echo signals and generates M consecutive in-phase signals and M consecutive quadrature-phase signals accordingly, wherein M is an integer greater than 1. The first sensing circuit is coupled to the I/Q signal generator to receive the M consecutive in-phase signals and is configured to perform integration and analog-to-digital conversion on the M consecutive in-phase signals to generate a first digital data. The second sensing circuit is coupled to the I/Q signal generator to receive the M consecutive quadrature-phase signals and is configured to perform integration and analog-to-digital conversion on the M consecutive quadrature-phase signals to generate a second digital data.

Abstract: A signaling device that provides for passive radar detection. An incoming radar signal is reflected back outward away from the device with increased power. The incoming radar signal can also power a harmonic transceiver and generate a harmonic signal that is transmitted outward away from the device. The signaling device can also include one or more powered components to further transmit an outgoing signal.

Abstract: A motor vehicle having at least one radar sensor, which is mounted behind a radome, formed by a component of the motor vehicle to be radiated through, and/or having a radome, wherein the motor vehicle further includes a reference structure having at least one radar-detectable marker, which can be controlled by an adjusting apparatus and moved into a measuring position in the detection area of a radar sensor outside the radome, and a control apparatus configured to control the adjusting apparatus, based on a trigger signal, for moving the reference structure into the measuring position and to evaluate radar data recorded by the radar sensor describing the reference structure in the measuring setting through a comparison with a comparison data set stored in the control apparatus and recorded without deposition on the radome for detection of the potential deposition. The trigger signal indicates a potential deposition, which restricts the performance of the radar sensor, on the radome.

Abstract: Aspects of this disclosure relate to systems and methods for calibration of antenna arrays. The calibration may be based on determining a reference value for the beamformer derived from measurements of phase and/or amplitude for each channel within the beamformer. The measurements of phase and/or amplitude can be stored in non-volatile memory. Using a difference between the reference value and the measured values for each channel, a portion of a global configuration table may be copied to each channel's memory. Each channel can be separately calibrated based on the portion of the global configuration table copied to the local memory of each channel.

Abstract: In an embodiment, a method of operating a radar includes: transmitting a radiation pulse with the radar during an active mode; asserting a sleep flag after transmitting the radiation pulse; turning off a crystal oscillator circuit of the radar after the sleep flag is asserted; clocking a counter of the radar with a low power oscillator during a low power mode after the sleep flag is asserted; asserting a timer flag when the counter reaches a first threshold; and transitioning into the active mode after the timer flag is asserted.

Abstract: A radar system for generating a radar image of a scene. Receive radar measurements of reflectivity of each point in the scene measured by receivers. Solve a radar image recovery (RIR) problem using stored data to produce the radar image. By connecting the radar measurements to a shift of a reflection field with a receiver shift. The receiver shift defines an error between stored receiver positions and actual receivers positions, the reflection field is generated by reflecting the transmitted field from the scene in accordance with the reflectivity of each point in the scene. Connecting the reflection field to a shift of an incident field with a transmitter shift. The transmitter shift defines an error between stored transmitter positions and actual transmitters positions. Solve as a multilinear problem of joint estimation of the reflectivity of each point in the scene, the receiver shift, and the transmitter shift.

Abstract: Trapped or confined individuals may be located and rescued by detecting their vital signs (e.g., chest movement or heart beat) using reflected, radio frequency signals over a range of multiple antenna polarities.

Abstract: Embodiments described herein can address these and other issues by using radar machine learning to address the radio frequency (RF) to perform object identification, including facial recognition. In particular, embodiments may obtain IQ samples by transmitting and receiving a plurality of data packets with a respective plurality of transmitter antenna elements and receiver antenna elements, where each data packet of the plurality of data packets comprises one or more complementary pairs of Golay sequences. I/Q samples indicative of a channel impulse responses of an identification region obtained from the transmission and reception of the plurality of data packets may then be used to identify, with a random forest model, a physical object in the identification region.

Abstract: A method carried out in a radionavigation system (2), the radionavigation system (2) comprising a receiver (4) and a radionavigation infrastructure (6), the radionavigation infrastructure comprising a plurality of satellite-borne transmitters (8, 8?, 8?, 8??), and encryption component (10) configured for communication with the transmitters (8, 8?, 8?, 8??) and the receiver (4). The method comprises the following, for one or more given transmitters (8) of the plurality of satellite-borne transmitters (8, 8?, 8?, 8??). In the radionavigation infrastructure (6), a series of keys k2,i are generated in respect of a predetermined authentication interval [0,T] of duration T and commencing at t=0 and a spreading code-encrypted signal e(t) is generated from a first radionavigation signal s1(t) using a keystream K1(t), the keystream K1(t) being generated with a secret key k1 of the radionavigation infrastructure (6).

Abstract: A millimeter-wave (mmW) imaging system comprises a mmW source configured to transmit mmW radiation to a target and a mmW imaging device. The mmW imaging device comprises an array of up-converter elements configured to convert backscatter radiation received from the target directly to visible light. The up-converter array has a first surface and a second surface. The mmW imaging device also comprises a first focusing lens optically coupled to the first surface of the up-converter array and configured to direct backscatter radiation received from the target to the up-converter elements. The mmW imaging device further comprises an an array of photodetectors. The photodetector array has a first surface and a second surface. The first surface of the photodetector array is configured to receive visible light emitted by the up-converter elements. The photodetector array is configured to produce electrical signals indicative of an optical image of the target.

Abstract: The present disclosure provides a two-dimensional antenna system. The two-dimensional antenna system includes a transmitting antenna array and a receiving antenna array. The transmitting antenna array includes one or more circularly polarized transmitting antennas having a first direction of rotation. The receiving antenna array includes two or more first circularly polarized receiving antennas having a second direction of rotation arranged in a first direction, and two or more second circularly polarized receiving antennas having the second direction of rotation arranged in a second direction. The first direction is perpendicular to the second direction, and the first direction of rotation is opposite to the second direction of rotation.

Abstract: A differential antenna includes a substrate formed of non-radio-frequency material and a pair of conductive microstrip lines formed on the substrate. A metallic sheet is supported and spaced apart from the pair of conductive microstrip lines by a plurality of support elements to form an air gap. The metallic sheet is patterned to include a plurality of differential radiating gaps disposed along the longitudinal axis of the antenna and above a gap between the pair of conductive microstrip lines. Multiple rows of metallic vias are formed in the substrate disposed and spaced apart laterally with respect to the gap between the pair of conductive microstrip lines to define two propagation air cavities in which radiation can propagate. The differential antenna is configured such that the radiation is differential-mode, second-order radiation, which is emitted from the differential antenna at the differential radiating gaps in the metallic sheet.

Abstract: A multi-beam telecommunications antenna system with a focusing device including a two-dimensional radiator array generating a plurality of beams simultaneously by setting amplitude-time parameters of the signals for each radiator. The antenna includes: a focusing system having an amplifying lens; a radiating device, for irradiating the amplifying lens and having a two-dimensional radiator array, is disposed at a distance from the amplifying lens and covers a projection area of beams at this distance; and a beam forming system. At least one sub-array of the radiators provides a beam in a set direction. For each beam, the beam forming system provides, for each radiator in the corresponding sub-array, amplitude-time parameters of the signal being transmitted to form a non-planar wavefront, which is equidistant across the amplifying lens to a planar wavefront of the beam. The radiating surface of the radiator array is outside a region of self-intersection of the non-planar wavefronts.

Abstract: Disclosed is a liquid crystal panel of a scanning antenna including a transmission and/or reception region in which a plurality of antenna units are arrayed, and a non-transmission and/or reception region, the liquid crystal panel including: a TFT substrate provided with a first dielectric substrate, a TFT supported by the first dielectric substrate, a gate bus line, a source bus line, and a patch electrode; a slot substrate provided with a second dielectric substrate, and a slot electrode formed on a first main surface of the second dielectric substrate and including a slot arranged so as to correspond to the patch electrode; a liquid crystal layer provided between the TFT substrate and the slot substrate and including a plurality of liquid crystal regions; and a plurality of sealing portions that respectively surround the plurality of liquid crystal regions and bond the TFT substrate and the slot substrate together.

Abstract: A radar antenna for a flight vehicle that follows a flight path comprises a radio frequency (RF) reflector, and separated first arrays of first RF feed elements to form, with the reflector, respective first fixed radar beams that are directed at the Earth and positionally offset with respect to each other, such that when the radar antenna follows the flight path, the respective first fixed radar beams trace respective first subswaths on the Earth that are separated from each other by respective subswath gaps.

Abstract: A hardware in the loop simulation and test system that includes a phased array antenna simulation system providing dynamic range and angle of arrival signals simulation and synchronizing for input into a system under test (SUT) that includes a phased array signal processing system along with related methods. Embodiments include system elements that increase precision of signal simulation to include reduced error in angular resolution.