Various examples for multi-tone continuous wave detection and ranging are disclosed herein. In some embodiments, an initial signal is generated using initial radio frequency (RF) tones, and is emitted as a multi-tone continuous wave signal. The initial signal is reflected from a target and received as a reflected signal. Resultant RF tones, including a frequency and a power, are determined from the reflected signal in a frequency domain. A frequency-domain sinusoidal wave is fitted to the resultant RF tones in the frequency domain, and a distance to the target is determined using a modulation of the frequency-domain sinusoidal wave.

A radar sensor in a motor vehicle has at least one antenna arrangement for emitting and receiving radar signals and a processing device for evaluating received radar signals. The antenna arrangement is controlled to simultaneously emit and receive radar signals both in a far frequency range and in a near frequency range, where the bandwidth of the near frequency range is greater than that of the far frequency range. The received radar signals of the near frequency range are evaluated as radar data of a higher distance resolution and received radar signals of the far frequency range are evaluated as radar data of a lower distance resolution.

A sensing system has transmitting antennas and receiving antennas. The placement of the sensing system is adapted to enhance the sensing system's ability to process the signals so as to provide information regarding the touch between fingertips, the pinching of fingers and the touching of objects.

A Multiple Input Multiple Output (MIMO) radar system and method of using it for target recovery are disclosed. The MIMO radar system comprises an array of distributed radiating elements configured to transmit signals towards a target scene, an array of distributed receiving elements configured to receive signals backscattered from the target scene, a sampling module configured to sample the signals received, and a hardware processor configured to recover from the samples position parameters of one or more targets. Range, direction and optionally velocity, are estimated via simultaneous 2D or 3D sparse matrix recovery, wherein all channels defined by transmitter-receiver pairs are processed together. The digital processing may be applied either in Nyquist or sub-Nyquist scheme, reducing the number of samples, transmit and/or receive antennas. The radar system is optionally further enhanced by cognitive transmission scheme where transmitted signals are distributed over a wide frequency range with vacancy bands left therein.

A method for operating a stepped frequency radar system is disclosed. The method involves performing stepped frequency scanning across a first frequency range using frequency steps of a first step size, the stepped frequency scanning performed using at least one transmit antenna and a two-dimensional array of receive antennas, changing from the first step size to a second step size, wherein the second step size is different from the first step size, and performing stepped frequency scanning across a second frequency range using the at least one transmit antenna and the two-dimensional array of receive antennas and using frequency steps of the second step size.

A generator of a frequency modulated radar signal, comprising: a generator of a periodic signal frequency modulated over a part T.sub.ramp of a period T, corresponding to a square signal of which the frequency varies linearly in a first frequency band B.sub.in of central frequency f.sub.in; an oscillator generating a sinusoidal signal of frequency f.sub.c>f.sub.in and comprised in a second frequency band B.sub.amp>B.sub.in and corresponding to the linear variation of the frequency of the radar signal; means coupled to an electrical supply input of the oscillator such that they generate a voltage for supplying the oscillator at the frequency of the frequency modulated periodic signal.

A digital FMCW radar is described that simultaneously transmits and receives digitally frequency modulated signals using multiple transmitters and multiple receivers and associated antennas. Several sources of nearby spillover from transmitters to receivers that would otherwise degrade receiver performance are subtracted by a cancellation system in the analog radio frequency domain that adaptively synthesizes an analog subtraction signal based on residual spillover measured by a correlator operating in the receivers' digital signal processing domains and based on knowledge of the transmitted waveforms. The first adaptive cancellation system achieves a sufficient reduction of transmit-receive spillover to avoid receiver saturation or other non-linear effects, but is then added back in to the signal path in the digital domain after analog-to-digital conversion so that spillover cancellation can also operate in the digital signal processing domain to remove deleterious spillover components.

Aspects of the disclosure are directed to apparatuses, systems and methods for radar processing. As may be implemented in accordance with one or more aspects herein, an apparatus may include receiver circuitry to receive and sample radar signals reflected from a target, and processing circuitry to carry out the following. Representations of the reflections are transformed into the time-frequency domain where they are oversampled. The oversampled representations of the reflections are inversely transformed to provide resampled reflections. Positional characteristics of the target may then be ascertained by constructing a range response characterizing the target based on the resampled reflections.

A signal processing method for a frequency-modulated continuous waveform (FMCW) radar system includes receiving a plurality of feedback signals from a plurality of targets and performing analog to digital conversion on the plurality of feedback signals to obtain a digital receiving signal corresponding to the plurality of feedback signals, performing a window function on the digital receiving signal to obtain a window transformation signal corresponding to the digital receiving signal, performing time-domain to frequency-domain conversion on the window transformation signal to obtain a spectrum signal of the window transformation signal, performing two beat frequency detections on the spectrum signal, and determining distances and speeds of the plurality of targets in comparison to the FMCW radar system according to results of the two beat frequency detections.

A method for ascertaining operating data of a radar sensor, including transmitting defined data of a first subsequence of ramp signals to an RF component of the radar sensor; ascertaining the data of the remaining subsequences of the ramp signals from the defined values of the first subsequence with the aid of the RF component; and storing the ascertained data of the remaining subsequences in a first memory of the RF component.