A multichannel radar system comprising a set of antennas each receiving a sequence of chirps reflected from plurality of objects, a range detector generating a set of range bins for each chirp, a beam former operative to generate a set of dominant frequency components from a group of range bins picked from the set of range bins across the set of antennas, a nearness detector for separating the set of dominant frequencies into a first set of dominant frequencies and a second set of dominant frequencies, a frequency subtractor configured to shift the each dominant frequency in the first set of dominant frequencies by its phase by a first value to form a third set of phase shifted dominant frequencies, and a Doppler estimator estimating a Doppler frequency of the each dominant frequency in the set of dominant frequencies from the third set of phase shifted dominant frequencies and the second set of dominant frequencies.

A method for calibrating a cascaded radar system includes transmitting first radar transmission signal from a radar device. First radar reflection signals corresponding to the respective first radar transmission signal reflected from calibration target are received at each of the radar devices. The first radar reflection signals are demodulated to generate first baseband signals at each of the radar devices. A second radar transmission signal is modulated with respect to the first radar transmission signal at the respective one of the radar devices. The second radar transmission signal is transmitted from the respective one of the radar devices and are received as second radar reflection signals at each of the radar devices. The second radar reflection signals are demodulated to generate second baseband signals at each of the radar devices, and each of the radar devices are calibrated based on the first and second baseband signals.

Methods and apparatus for generating a target signal with desired phase shift information. In embodiments, a system receives an input target signal having a first frequency and combines the input target signal with an oscillator signal to generate a first output signal having a second frequency. The oscillator signal is generated using a digital component that imparts phase-shift information into the oscillator signal. The first output signal is combined with a fixed frequency oscillator signal to generate a second output signal corresponding to a signal reflected from a target.

A self-testing measuring system includes at least three modes: an operating mode and at least two test modes. In a third test mode, a digital signal generating unit stimulates the digital input circuit directly by means of test signals. In a second test mode, the digital signal generating unit stimulates the analogue signal string and the digital input circuit by means of test signals. In a first test mode, the digital signal generating unit stimulates the analogue signal string, the measuring unit (typically an ultrasound transducer) and the digital input circuit by means of test signals, thereby allowing this signal string to be tested. In the operating mode, the digital signal generating unit stimulates the analogue signal string, the measuring unit (typically an ultrasound transducer) and the digital input circuit by means of output signals, thereby allowing the signal string to be monitored for parameter compliance.

A frequency-modulated continuous-wave (FMCW) radar system for level or distance measurement in which a frequency modulated signal to be transmitted to a target is mixed with an echo signal from the target to produce a beat signal that passes through an analog filter before being digitized and processed in a digital processor to determine the level or distance to be measured, where a test signal is generated by a signal generator, and a switch is controlled to connect the beat signal or the test signal to the analog filter, the signal generator generates the test signal as a broadband signal having a periodic waveform, e.g., a square wave, and the digital processor calculates a spectrum of the digitized filtered test signal by Fast Fourier Transform and generates a fault signal if the spectrum differs from a reference spectrum by a predetermined amount to allow for failure detection.

A multichannel radar system comprising a set of antennas each receiving a sequence of chirps reflected from plurality of objects, a range detector generating a set of range bins for each chirp, a beam former operative to generate a set of dominant frequency components from a group of range bins picked from the set of range bins across the set of antennas, a nearness detector for separating the set of dominant frequencies into a first set of dominant frequencies and a second set of dominant frequencies, a frequency subtractor configured to shift the each dominant frequency in the first set of dominant frequencies by its phase by a first value to form a third set of phase shifted dominant frequencies, and a Doppler estimator estimating a Doppler frequency of the each dominant frequency in the set of dominant frequencies from the third set of phase shifted dominant frequencies and the second set of dominant frequencies.

The invention relates to a self-testing measuring system (SS) which may have at least three modes: an operating mode and at least two test modes. In a third test mode, a digital signal generating unit (DSO) stimulates the digital input circuit (DSI) directly by means of test signals, thereby allowing this signal string to be tested. In a second test mode, the digital signal generating unit (DSO) stimulates the analogue signal string (DR, AS) and the digital input circuit (DSI) by means of test signals, thereby allowing this signal string to be tested. In a first test mode, the digital signal generating unit (DSO) stimulates the analogue signal string (DR, AS), the measuring unit (TR) (typically an ultrasound transducer) and the digital input circuit (DSI) by means of test signals, thereby allowing this signal string to be tested and monitored for parameter compliance, in particular in respect of signal amplitudes. In the operating mode, the digital signal generating unit (DSO) stimulates the analogue signal string (DR, AS), the measuring unit (TR) (typically an ultrasound transducer) and the digital input circuit (DSI) by means of output signals, thereby allowing the signal string to be monitored for parameter compliance, in particular in respect of signal amplitudes.

The present disclosure relates to adjusting a suppression signal for suppressing a radio frequency (RF) interference signal in a received signal. A method includes generating an RF signal having a first frequency offset from an interference frequency; generating the suppression signal having a second frequency offset from the interference frequency; coupling the suppression signal into the received signal in order to generate a receiver input signal; mixing the receiver input signal with the RF signal in order to generate a mixer output signal; adjusting an amplitude of the suppression signal in order to align amplitudes of different components of the mixer output signal; coupling an adjusted suppression signal, having the interference frequency and the adjusted amplitude, into the received signal; and varying a phase of the adjusted suppression signal in order to reduce a frequency component of the mixer output signal that has the first frequency offset.

In a radar system, a cancellation circuit is described for compensating for the effects of spillover between each transmitter and a receiver. The cancellation circuit is configured for applying cancellation signals to the receiver which are generated in a cancellation filter utilizing a primary impulse response characteristic corresponding to the spillover, a signal to be transmitted from each transmitter in the radar system, and a range profile output from the receiver. The cancellation circuit may also include a secondary impulse response characteristic module and a dithering module to improve the sensitivity of the receiver.

An electronic device may include radar circuitry. Control circuitry may calibrate the radar circuitry using a multi-tone calibration signal. A first mixer may upconvert the calibration signal for transmission by a transmit antenna. A de-chirp mixer may mix the calibration signal output by the first mixer with the calibration signal as received by a receive antenna or loopback path to produce a baseband multi-tone calibration signal. The baseband signal will be offset from DC by the frequency gap. This may prevent DC noise or other system effects from interfering with the calibration signal. The control circuitry may sweep the first mixer over the radio frequencies of operation of the radar circuitry to estimate the power droop and phase shift of the radar circuitry based on baseband calibration signal. Distortion circuitry may distort transmit signals used in spatial ranging operations to invert the estimated power droop and phase shift.