A light sensing system includes a plurality of light-emitting devices arranged to have a first optical axis and a plurality of light-receiving devices arranged to have a second optical axis, the second optical axis being parallel with the first optical axis. The plurality of light-emitting devices and the plurality of light-receiving devices are formed to have a monolithically integrated structure, and the first optical axis and the second optical axis are substantially coaxial to each other, thus improving the efficiency of light reception.

A light detection and ranging (LIDAR) system includes an optical source to emit an optical beam, and free-space optics coupled with the optical source to focus the optical beam at a first focal plane, where a local oscillator (LO) signal is generated from a partial reflection of the optical beam from a partially-reflecting surface proximate to the first focal plane, and where a transmitted portion of the optical beam is directed toward a scanned target environment. The free-space optics configured to focus the LO signal and a target return signal at a second focal plane comprising a conjugate focal plane to the first focal plane. The system also includes a photodetector with a photosensitive surface proximate to the conjugate focal plane to mix the LO signal with the target return signal to generate target information.

A lidar sensor comprising a laser, an optical sensor, and a processor. The lidar sensor can determine a distance to one or more objects. The lidar sensor can optionally embed a code in beams transmitted into the environment such that those beams can be individually identified when their corresponding reflection is received.

A mobile computing device antenna according to one example includes a folded monopole element, a ground plane coupled to the folded monopole element by an antenna feed, a parasitic element that couples the folded monopole element to the ground plane, and a metal frame that encompasses the folded monopole element, the ground plane, and the parasitic element, where the metal frame is coupled to the ground plane by a plurality of ground points.

A system and method for selecting a polarization for a particular antenna in an antenna array is disclosed. The system comprises an antenna array, wherein each antenna is adapted to receive and transmit horizontally and vertically polarized signals. The system also includes a switching network that is adapted to select the vertical or horizontal polarized signal for each antenna in the antenna array. The switching network also allows selection of a circular polarized signal from one or more of the antenna elements in the antenna array. This allows the AoX to be more accurate, as it is able to receive horizontally and vertically polarized signals, rather than just circular polarized signals, thereby improving its accuracy. The ability to receive circular polarized signals may be beneficial during reference periods to acquire the proper gain and frequency.

A system and method for selecting a polarization for a particular antenna in an antenna array is disclosed. The system comprises an antenna array, wherein each antenna is adapted to receive and transmit horizontally and vertically polarized signals. The system also includes a switching network that is adapted to select the vertical or horizontal polarized signal for each antenna in the antenna array. The switching network also allows selection of a circular polarized signal from one or more of the antenna elements in the antenna array. This allows the AoX to be more accurate, as it is able to receive horizontally and vertically polarized signals, rather than just circular polarized signals, thereby improving its accuracy. The ability to receive circular polarized signals may be beneficial during reference periods to acquire the proper gain and frequency.

To detect return light pulses in a lidar system when scanning in the forward-scanning and reverse-scanning directions, a light source may transmit first light pulses having a first wavelength when scanning in the forward-scanning direction and may transmit second light pulses having a second wavelength when scanning in the reverse-scanning direction. A diffractive optical element (DOE) is configured to deflect the two wavelengths in opposite directions, so that light pulses are transmitted ahead of the field of view of the detector in the scanning direction of the lidar system. A controller may determine the scanning direction of a scanner in the lidar system and transmit a control signal to a light source indicative of a wavelength that corresponds to the scanning direction. The light source may then transmit light pulses at the requested wavelength.

A multi-port antenna and associated systems having extremely wide bandwidth and capable of maintaining directivity as frequency decreases and is made arbitrarily low, allowing DF systems to operate to arbitrarily low frequency regardless of size. Construction may be rugged, lightweight, and low cost, allowing reliable service in harsh environments. The systems allow utilization of both the E and H fields occupying a common area of space. The disclosed DF system takes advantage of knowledge of the as-installed array manifold, uses pattern matching to determine the angle of arrival (AoA) of incoming waves, and enhances sensitivity by using integration on cross-correlation products between the multiple ports to achieve SNR improvement.

A mm-wave RFID tag interrogation apparatus includes multiple transmitting antennas, and multiple receiving antennas. The transmitting and receiving antennas are spatially distributed and oriented in orthogonal polarization states. A transmitter is coupled to the transmitting antennas, and transmits a corresponding multiple number of separable mm-wave signals. A receiver coupled to the receiving antennas is configured to extract separable components of received mm-wave signals. A processing unit processes the extracted signal components using a synthetic aperture algorithm. An RFID tag, readable by the interrogation apparatus, includes meander-line conductive elements arranged to encode information spatially on a substrate.

The invention relates to a method for estimating the direction of arrival of an electromagnetic wave at an antenna array (2), comprising the steps of: estimating (202) a covariance matrix of signals acquired by the antenna array (2); calculating (204) a normalised eigenvector of the covariance matrix; correlating (205) the normalised eigenvector with a first reference table and a second reference table so as to produce a first correlation spectrum and a second correlation spectrum comprising correlation indices associated, respectively, with different directions of arrival; constructing (312) a third reference table by linear combination of the first reference table and the second reference table with a polarisation component of the electromagnetic wave in the first direction and the second direction, respectively; correlating (314) the normalised eigenvector with the third reference table so as to produce a third correlation spectrum comprising correlation indices associated with different directions of arrival; identifying (316) a direction of arrival associated with a maximum correlation index of the third correlation spectrum.