Abstract: A receive extender in an integrated circuit may include: N phase-adjustment circuits that adjust phases of N receive signals from N receive antennas; and an N:1 demultiplexer that coherently combines the N receive signals into an output signal, which is provided to the transceiver chip. Moreover, a transmit extender in the integrated circuit may include: a 1:M multiplexer that coherently separates a transmit signal from the transceiver chip into M transmit signals, where N and M are non-zero integers that may be different; and M phase-adjustment circuits that adjust phases of the M transmit signals, which are provided to M transmit antennas. Note that the integrated circuit may be coupled to a second integrated circuit that phase shifts the output signal and the transmit signal based at least in part on the oscillator signal. Moreover, control signals between the integrated circuit and the second integrated circuit may be synchronized.

Abstract: A radar antenna calibration method includes: forming a detection matrix from signals detected by an arrangement of receive antennas in response to chirps transmitted by an arrangement of transmit antennas, the detection matrix having multiple rows corresponding to the chirps, multiple columns corresponding to a signal sample, and multiple planes corresponding the receive antennas; deriving a range matrix by performing a frequency transform on a portion of each row of the detection matrix; extracting a slice of the range matrix, with different rows of the slice being associated with different chirps and with different receive antennas; deriving a velocity matrix from the extracted slice by performing a frequency transform on a portion of each column of the extracted slice; analyzing the velocity matrix to determine a current peak width; and adjusting, based on the current peak width, phase shifts associated with one or more of the receive antennas.

Abstract: One illustrative integrated electromagnetic-acoustic sensor includes: a ground plane; a patch antenna above the ground plane to send or receive an electromagnetic (EM) signal having an EM signal frequency; and an array of capacitive micromachined acoustic transducers formed by cavities between the patch antenna and a base electrode to send or receive an acoustic signal having an acoustic signal frequency. One illustrative sensing method includes: driving or sensing a EM signal between a ground plane and a patch antenna; and driving or sensing an acoustic signal between the patch antenna and a base electrode, the base electrode and the patch antenna having an array of capacitive micromachined acoustic transducer cavities therebetween.

Abstract: Multiple-input multiple-output (MIMO) radar systems are equipped with channel extenders to further increase the number of receive and/or transmit antennas that can be supported by a given radar transceiver. One illustrative radar system includes: a radar transceiver to generate a transmit signal and to downconvert at least one receive signal; and a receive-side extender that couples to a set of multiple receive antennas to obtain a set of multiple input signals, that adjustably phase-shifts each of the multiple input signals to produce a set of phase-shifted signals, and that couples to the radar transceiver to provide the at least one receive signal, the at least one receive signal being a sum of the phase-shifted signals. An illustrative receive-side extender includes: multiple phase shifters each providing an adjustable phase shift to a respective input signal; a power combiner that forms a receive signal by combining outputs of the multiple phase shifters.

Abstract: A centralized occupancy detection system enables monitoring of multiple seats, or more generally, multiple stations, with a single sensor. One illustrative vehicle includes: one or more stations each configured to accommodate an occupant of the vehicle, a radar-reflective surface, and a radar transceiver configured to use the radar-reflective surface to detect an occupant of at least one of the stations. Another illustrative vehicle includes: multiple stations to each accommodate an occupant of the vehicle, and a radar transceiver configured to examine each of the multiple stations to determine whether that station has an occupant.

Abstract: An improved circuit configuration is disclosed for calibrating and/or verifying the operation of phase shifters in a phased array radar system. In one illustrative embodiment, a method includes: (i) programming a set of phase shifters to convert a radio frequency signal into a set of channel signals; (ii) splitting off a monitor signal from each channel signal while coupling the set of channel signals to a set of antenna feeds; and (iii) while taking the monitor signals in pairs associated with adjacent channels, measuring a relative phase between each pair of monitor signals.

Abstract: A radar antenna calibration method includes: forming a detection matrix from signals detected by an arrangement of receive antennas in response to chirps transmitted by an arrangement of transmit antennas, the detection matrix having multiple rows corresponding to the chirps, multiple columns corresponding to a signal sample, and multiple planes corresponding the receive antennas; deriving a range matrix by performing a frequency transform on a portion of each row of the detection matrix; extracting a slice of the range matrix, with different rows of the slice being associated with different chirps and with different receive antennas; deriving a velocity matrix from the extracted slice by performing a frequency transform on a portion of each column of the extracted slice; analyzing the velocity matrix to determine a current peak width; and adjusting, based on the current peak width, phase shifts associated with one or more of the receive antennas.

Abstract: An improved circuit configuration is disclosed for calibrating and/or verifying the operation of phase shifters in a phased array radar system. In one illustrative embodiment, a method includes: (i) programming a set of phase shifters to convert a radio frequency signal into a set of channel signals; (ii) splitting off a monitor signal from each channel signal while coupling the set of channel signals to a set of antenna feeds; and (iii) while taking the monitor signals in pairs associated with adjacent channels, measuring a relative phase between each pair of monitor signals.

Abstract: Automotive radar systems may employ a reconfigurable connection of antennas to radar transmitters and/or receivers. An illustrative embodiment of an automotive radar system includes: a radar transmitter; a radar receiver; and a digital signal processor coupled to the radar receiver to detect reflections of a signal transmitted by the radar transmitter and to derive signal measurements therefrom. At least one of the radar transmitter and the radar receiver are switchable to provide the digital signal processor with signals from each of multiple combinations of transmit antenna and receive antenna.

Abstract: A novel system that allows for 3D radar detection that simultaneously captures the lateral and depth features of a target is disclosed. This system uses only a single transceiver, a set of delay-lines, and a passive antenna array, all without requiring mechanical rotation. By using the delay lines, a set of beat frequencies corresponding to the target presence can be generated in continuous wave radar systems. Likewise, in pulsed radar systems, the delays also allow the system to determine the 3D aspects of the target(s). Compared to existing solutions, the invention, in embodiments, allows for the implementation of simple, reliable, and power efficient 3D radars.

Abstract: Automotive radar systems may employ a reconfigurable connection of antennas to radar transmitters and/or receivers. An illustrative embodiment of an automotive radar system includes: a radar transmitter; a radar receiver; and a digital signal processor coupled to the radar receiver to detect reflections of a signal transmitted by the radar transmitter and to derive signal measurements therefrom. At least one of the radar transmitter and the radar receiver are switchable to provide the digital signal processor with signals from each of multiple combinations of transmit antenna and receive antenna.

Abstract: A radar antenna calibration method includes: forming a detection matrix from signals detected by an arrangement of receive antennas in response to chirps transmitted by an arrangement of transmit antennas, the detection matrix having multiple rows corresponding to the chirps, multiple columns corresponding to a signal sample, and multiple planes corresponding the receive antennas; deriving a range matrix by performing a frequency transform on a portion of each row of the detection matrix; extracting a slice of the range matrix, with different rows of the slice being associated with different chirps and with different receive antennas; deriving a velocity matrix from the extracted slice by performing a frequency transform on a portion of each column of the extracted slice; analyzing the velocity matrix to determine a current peak width; and adjusting, based on the current peak width, phase shifts associated with one or more of the receive antennas.

Abstract: A radar detection method with receive antenna calibration includes: forming a detection matrix from signals detected by an arrangement of receive antennas in response to chirps transmitted by an arrangement of transmit antennas, the detection matrix having multiple rows corresponding to the chirps, multiple columns corresponding to a sample of the signals, and multiple planes corresponding the receive antennas; deriving a range matrix by performing a frequency transform on a portion of each row of the detection matrix; deriving a velocity matrix by performing a frequency transform on a portion of each column of the range matrix; deriving a direction-of-arrival matrix by performing a frequency transform on a portion of one or more layers of the velocity matrix; analyzing the direction-of-arrival matrix to determine a current peak width; and adjusting, based on the current peak width, phase shifts associated with one or more antennas.

Abstract: One illustrative embodiment of a radar system includes: a signal generator, a variable phase shifter element, and a mixer. The signal generator supplies a frequency modulated continuous wave (FMCW) signal to a transmit antenna protected by a housing, which causes a housing reflection having a frequency offset from the FMCW signal. The variable phase shifter element derives a reference signal from the FMCW signal by applying a time-dependent phase shift based on the frequency offset. The mixer obtains a receive signal including said housing reflection and multiplies the receive signal with the reference signal to produce a downconverted signal.

Abstract: An automotive radar system that is switchable between one or more high power modes and one or more increased channel modes. The radar system includes multiple transmit antennas, an integrated circuit including a transmit chain generating a positive transmit signal and a negative transmit signal that together form a differential transmit signal, and a coupling interface. The coupling interface configurably couples the differential transmit signal to two transmit antennas of the multiple transmit antennas to selectively drive the two transmit antennas in either a differential mode or in a power-combining mode that combines power from the positive transmit signal and negative transmit signal to drive a first transmit antenna of the multiple transmit antennas while isolating a second transmit antenna of the two transmit antennas.

Abstract: An improved circuit configuration is disclosed for calibrating and/or verifying the operation of phase shifters in a phased array radar system. In one illustrative embodiment, a method includes: (i) programming a set of phase shifters to convert a radio frequency signal into a set of channel signals; (ii) splitting off a monitor signal from each channel signal while coupling the set of channel signals to a set of antenna feeds; and (iii) while taking the monitor signals in pairs associated with adjacent channels, measuring a relative phase between each pair of monitor signals.

Abstract: An array of one or more integrated circuits includes at least one local input port to receive a chirp signal from a local generator; one or more primary input ports to each receive a respective chirp signal from a remote source; a primary switch arrangement operable to switch between the chirp signals from the at least one local input port and the one or more primary input ports to produce a composite signal having a chirp sequence with at least one chirp that begins during a settling period of a previous chirp; and one or more primary output ports to supply a local oscillator signal to a transmitter and a receiver based on the composite signal. The roles of master circuit and follower circuit can change during operation of the array.

Abstract: A multi-antenna signal encoding method comprises receiving an antenna signal and a reference signal a first mixer; producing, using the first mixer, a down-converted signal based on the antenna signal and the reference signal; receiving, at one or more second mixers, second antenna signals and second reference signals orthogonal to the first reference signal; producing one or more second down-converted signals based on the one or more second antenna signals and the one or more second reference signals; converting, using an analog-to-digital converter, a summation signal corresponding to a sum of the first down-converted signal and the one or more second down-converted signals, into a digital receive-signal; and extracting, at a processor, a plurality of digital signals from the digital receive-signal, wherein each of the plurality of digital signals corresponds to one of the first antenna signal and the one or more second antenna signals.

Abstract: Disclosed active reflector apparatus and methods that inhibit self-induced oscillation. One illustrative apparatus embodiment includes an amplifier and an adjustable phase shifter. The amplifier amplifies a receive signal to generate a transmit signal, the transmit signal causing interference with the receive signal. The adjustable phase shifter modifies the phase of the transmit signal relative to that of the receive signal to inhibit oscillation. A controller may periodically test a range of settings for the adjustable phase shifter to identify undesirable phase shifts prone to self-induced oscillation, and may maintain the phase shift setting at a value that inhibits oscillation.

Abstract: Automotive radar systems may employ a reconfigurable connection of antennas to radar transmitters and/or receivers. An illustrative embodiment of an automotive radar system includes: a radar transmitter; a radar receiver; and a digital signal processor coupled to the radar receiver to detect reflections of a signal transmitted by the radar transmitter and to derive signal measurements therefrom. At least one of the radar transmitter and the radar receiver are switchable to provide the digital signal processor with signals from each of multiple combinations of transmit antenna and receive antenna.