A method includes generating a first modulated continuous wave from a generating location; transmitting the first modulated continuous wave to an object positioned at a distance from the generating location; generating a second modulated continuous wave from the generating location, wherein the second modulated continuous wave is generated at a predetermined time that is different from a predetermined time at which the first modulated continuous wave is generated; receiving, at a mixer, the first modulated continuous wave from the object; receiving, at the mixer, the second modulated continuous wave from the generating location; mixing the received first modulated continuous wave with the second modulated continuous wave to produce a beat signal to determine a range of the object from the generating location; and outputting the determined range of the object from the generating location.

An apparatus includes an extendable wand, and a sensor head coupled to the wand. The sensor head includes a continuous wave metal detector (CWMD) and a radar. When the wand is collapsed, the wand and the sensor head collapse to fill a volume that is smaller than a volume filled by the sensor head and the wand when the wand is extended. Frequency-domain data from a sensor configured to sense a region is accessed, the frequency-domain data is transformed to generate a time-domain representation of the region, a first model is determined based on the accessed frequency-domain data, a second model is determined based on the generated time-domain representation, the second model being associated with a particular region within the sensed region, and a background model that represents a background of the region is determined based on the first model and the second model.

Apparatus and associated methods relate to enabling a radar system to use different sensing mechanisms to estimate a distance from a target based on different detection zones (e.g., far-field and near-field). In an illustrative example, a curve fitting method may be applied for near-field sensing, and a Fourier transform may be used for far-field sensing. A predetermined set of rules may be applied to select when to use the near-field sensing mechanism and when to use the far-field mechanism. The frequency of a target signal within a beat signal that has less than two sinusoidal cycles may be estimated with improved accuracy. Accordingly, the distance of a target that is within a predetermined distance range (e.g., two meters range for 24 GHz ISM band limitation) may be reliably estimated.

The present disclosure relates to apparatuses and methods for a radar device. For example, an antenna device has a first set of antennas to establish first propagation channels and a second set of antennas to establish second propagation channels. A signal processing device determines a first differential phase shift among first radar signals propagating via the first propagation channels and a second differential phase shift among second radar signals propagating via the second propagation channels. Antennas of the first set are located at positions that generate the first differential phase shift for a first multitude of target angles, and antennas of the second set are located at positions that generate the second differential phase shift for a second multitude of target angles. The processing device determines an angular position of a target object as a unique target angle that is part of the first and second multitude of target angles.

A radar system comprises a transmitter and a receiver. The radar system is operable to define a near range and a far range. The radar system is operable to, during each one of a plurality of time intervals, repeatedly transmit, via the transmitter, a plurality of OFDM symbols. The transmitter is operable to select a transmit power for the transmission during the one of the time intervals based on from which of the near range and the far range reflections of the OFDM symbols are to be received during the one of the time intervals. The receiver is operable to receive reflections of the OFDM symbols, and process, in the receiver, the reflections of the OFDM symbols to detect objects within the near range and the far range.

A method for calibrating a radar system includes generating an RF oscillator signal and distributing the RF oscillator signal to a plurality of phase shifters each providing a respective phase-shifted RF oscillator signal; receiving the phase-shifted RF oscillator signals by corresponding radar chips and radiating the phase-shifted RF oscillator signal via a first RF output channel of a first one of the radar chips; receiving a back-scattered signal by at least one RF input channel of each radar chip and generating a plurality of base-band signals by down-converting the received signals into a base band using the phase-shifted RF oscillator signals received by the corresponding radar chips; determining a phase for each base-band signal; and adjusting the phase shifts caused by the phase shifters such that the phases of the base-band signals match a predefined phase-over-antenna-position characteristic.

Examples of imaging systems are described herein which may implement microwave or millimeter wave imaging systems. Examples described may implement partitioned inverse techniques which may construct and invert a measurement matrix to be used to provide multiple estimates of reflectivity values associated with a scene. The processing may be partitioned in accordance with a relative position of the antenna system and/or a particular beamwidth of an antenna. Examples described herein may perform an enhanced resolution mode of imaging which may steer beams at multiple angles for each measurement position.

A distance measuring apparatus according to an embodiment includes, a filter section configured to perform band limitation on a transmission signal and output the transmission signal, and to perform band limitation on a reception signal from an antenna section and output the reception signal, a distance measuring section configured to perform a distance measurement computation based on the transmission signal and the reception signal, and to obtain a delay of a signal passing through the filter section and perform calibration of the distance measurement computation, a signal interruption section configured to interrupt transmission of a signal between the filter section and the antenna section, and a control section configured to control the signal interruption section to interrupt the transmission of the signal during a period of the calibration.

An autonomous vehicle (AV) includes a radar sensor system and a computing system that computes velocities of an object in a driving environment of the AV based upon radar data that is representative of radar returns received by the radar sensor system. The AV can be configured to compute a first velocity of the object based upon first radar data that is representative of the radar return from a first time to a second time. The AV can further be configured to compute a second velocity of the object based upon second radar data that includes at least a portion of the first radar data and further includes additional radar data representative of a radar return received subsequent to the second time. The AV can further be configured to control one of a propulsion system, a steering system, or a braking system to effectuate motion of the AV based upon the computed velocities.

A vehicle radar sensor utilizes Frequency Modulated Continuous Wave (FMCW) radar signals that incorporate non-uniform FMCW chirps having chirp profiles that differ from one another to sense one or more parameters of one or more objects in a field of view of the radar sensor. The chirp profiles may differ from one another in various manners, e.g., based on starting frequency, repetition interval, duration and/or slope, and among other advantages, may be used to enhance sensing of various parameters such as range, Doppler/velocity and/or angle.