An electronically steerable phased array and switching network connected to an FMCW radar transceiver to enable a low-cost monopulse tracking system that covers a wide field of regard using electronic beam steering. In a first mode, beamformer integrated circuits (BFICs) at each element in the array are switched synchronously with transmit/receive (T/R) switches located at the subarray level. This allows the entire aperture to be switched between transmission and reception, enabling the FMCW radar transceiver to be operated in a pulsed configuration. In a second mode, a portion of the T/R switches at the subarray level and all of the connecting BFICs at the element level are fixed in either transmitting or receiving mode, allowing separate portions of the aperture to concurrently transmit or receive. The arrangement of transmitting and receiving subarrays can be dynamically reconfigured to allow for accurate bearing and azimuth estimation using alternating monopulse.

Techniques and apparatuses are described for radar angular ambiguity resolution. These techniques enable a target's angular position to be determined from a spatial response that has multiple amplitude peaks. Instead of solely considering which peak has a highest amplitude, the techniques for radar angular ambiguity resolution select a frequency sub-spectrum, or multiple frequency sub-spectrums, that emphasize amplitude or phase differences in the spatial response and analyze an irregular shape of the spatial response across a wide field of view to determine the target's angular position. In this way, each angular position of the target has a unique signature, which the radar system can determine and use to resolve the angular ambiguities. Using these techniques, the radar can have an antenna array element spacing that is greater than half a center wavelength of a reflected radar signal that is used to detect the target.

A system and method for ice crystal detection and qualification are disclosed. The system for ice crystal detection may include an aircraft weather radar and processing circuitry. The aircraft weather radar may perform scans at one or more elevations at successive times. The processing circuitry may calculate power and reflectivity values based on the scans. The processing circuitry may further compare the power and reflectivity values to threshold values to determine the presence of ice water content. The processing circuitry may display different colors on a display for areas in which the power and reflectivity values are lower than the threshold values.

One embodiment of the present disclosure relates to a vehicle radar apparatus and a method of controlling the same. The radar apparatus according to the present embodiment may include an antenna unit including Nt transmitting antennas and Nr receiving antennas, wherein one of the Nt transmitting antennas is vertically offset from the other transmitting antennas, or one of the Nr receiving antennas is vertically offset from the other receiving antennas, a transceiver configured to control the Nt transmitting antennas to transmit a phase shift transmission signal having N different phase shift values (an) and control the Nr receiving antennas to receive a reflected signal reflected from a target, and a signal processor configured to determine a height (h) of the target based on a discrete phase shift value (a.sub.max) that is a phase shift value having the greatest reception power among N phase shift values.

A method for calibrating a phased array including an antenna array comprising a plurality of antenna elements, comprising the steps: measuring with a probe a first antenna element pattern of a first antenna element of the plurality of antenna elements; performing a spherical near-field to far-field transformation of the first antenna element pattern; transforming the far-field first antenna element pattern to a plane-wave spectrum; back transforming the plane-wave far-field first antenna element pattern to a reference point within the near-field of the antenna array; normalizing the first antenna element pattern according to, at least, the value at the phase center of the plane-wave near-field first antenna element pattern; and calibrating the first antenna element based, at least in the part, on the normalized first antenna element pattern.

A radar imaging method using an active antenna comprising N transmission channels and M reception channels, transmitting in bursts of pointing cycles, is disclosed. The antenna covers a given angular range during a detection time unit of duration T, said time unit corresponds to a burst in which the N transmission channels are focused successively in a number D.sub.e of pointing directions (di) such that: the pointing direction on transmission (di) is modified from recurrence to recurrence; each time unit of duration T comprising a periodic repetition of a number C of identical pointing cycles, each of these cycles comprising a number P of recurrences, the set of these P recurrences covers the D.sub.e pointing directions (di); at least one beam is formed in reception on each recurrence in a direction included in the angular range focused on transmission in the pointing direction corresponding to said recurrence.

In some aspects, a system may receive, from a first one-dimensional radar array, first information based at least in part on first reflections associated with an azimuthal plane. The system may further receive, from a second one-dimensional radar array, second information based at least in part on second reflections associated with an elevation plane. Accordingly, the system may detect an object based at least in part on the first information and may determine an elevation associated with the object based at least in part on the second information. Numerous other aspects are described.

Methods and apparatus for providing a generic beamforming system. A first beamforming level can process digitized array data to form subarrays and output subarray data for the formed subarrays. A second beamforming level can process the subarray data to form beams and output beamforming data for a plurality of modules. A third beamforming level can process the beamforming data to process the beamforming data and generate formed beams for the array.

An electronic device may include wireless circuitry having a set of two or more antennas coupled to voltage standing wave ratio (VSWR) sensors. The VSWR sensors may gather VSWR measurements from radio-frequency signals transmitted using the set of antennas. The antennas may be disposed on one or more substrates and/or may be formed from conductive portions of a housing. Control circuitry may process the VSWR measurements to identify the ranges between each of the antennas in the set of antennas and an external object. The control circuitry may process the ranges to identify an angular location of the external object with respect to the device. The control circuitry may adjust subsequent communications based, adjust the direction of a signal beam produced by a phased antenna array, identify a user input, or perform any other desired operations based on the angular location.

A radar apparatus with a transmission antenna array that outputs a high aspect ratio frequency modulation continuous wave (FMCW) transmission beam that illuminates a large field of regard in elevation and may be both electronically and mechanically scanned in azimuth. The weather radar apparatus includes a receive array and receive electronics that may receive the reflected return radar signals and digitally form a plurality of receive beams that may be used to determine characteristics of the area in the field of regard. The receive beams may be used to determine reflectivity of weather systems and provide a coherent weather picture. The weather radar apparatus may simultaneously process the receive signals into monopulse beams that may be used for accurate navigation as well as collision avoidance.