A method for self-calibrating a radar system includes forming a calibration loop-back signal path. The calibration loop-back signal path is configured for determining a passband response of each of a radio frequency (RF) signal path, a local oscillator (LO) signal path, and an intermediate frequency (IF) signal path of the radar system. The method also includes transmitting a set of calibration signals into the RF signal path and the LO signal path and measuring output signals from the IF signal path in a receiver of the radar system. The method further includes determining the passband response of each of the RF signal path, the LO signal path and the IF signal path from the measured output signals and compensating for distortions and/or non-linearities in the signal paths using the passband response of each signal path.

In a radar system, a marker is placed in the field of view of a transceiver. The marker receives the radar signal transmitted by the transceiver and retransmits, as a function of this radar signal, a diagnostic radar signal, for example originating from reflections of the collected signal inside the marker. Then, the transceiver, while collecting and processing the signal from the field of view to detect the targets therein, checks whether the diagnostic radar signal, interpreted as a target with characteristic position and amplitude, is present. If this does not match the expected signal, a malfunction is indicated. The marker may be activated periodically, for example only when system diagnostics is required. A variety of internal configurations of the marker can change the characteristic position, to create a movable and easily identifiable dummy target.

A radar system for determining a distance to another radar system includes a transceiver. The transceiver transmits a first Frequency Modulated Continuous Wave, FMCW, radar signal. The first FMCW radar signal includes a first sweep profile. The transceiver is receives a second FMCW radar signal. The second FMCW radar signal includes a second sweep profile which differs from the first sweep profile. The radar system further includes a mixer which generates a beat signal based on the first and second FMCW radar signals. The radar system further comprises a deskewing unit which deskews the beat signal by matching the sweep profiles of the first and second FMCW radar signals. Further a method for determining a distance between radar systems, a system for determining a distance between first and second radar systems and a method for determining a distance between first and second radar systems.

A measurement setup for measuring attenuation through an irregular surface of a device under test is described. The measurement setup includes a positioning system, a reference reflector, and a three dimensional imaging system. The measurement setup has a reference state and a measurement state, wherein respective images are taken in the different states. The imaging system is configured to compare the images taken in the reference state and the measurement state to determine the attenuation of the device under test. Further, a reference reflector as well as a method for measuring attenuation are described.

An apparatus for measuring a surface comprises first sensors, which are distributed two-dimensionally in space, said first sensors interacting with the surface in a contactless manner using a microwave range of electromagnetic signals, and the first sensors receive at least two of the microwave signals of the interaction with information relating to distances between the sensors and the surface as a reflection, the microwave signals of the interaction representing both dimensions of the space of two-dimensional distribution of the first sensors. A data processing unit receives said information on the distances, and determines at least one geometrical parameter of the surface on the basis of the information.

A method for checking the functional ability of an FMCW-based fill-level measuring device, which serves for measuring the fill level of a fill substance located in a container, as well as to a fill-level measuring device suitable for performing this method. For checking the functional ability, a microwave signal is produced, whose frequency change differs from the frequency change of the measurement signal used during regular measurement operation. By comparing the frequency of the difference signal resulting from the microwave signal with a predetermined reference frequency, it is ascertained, whether the fill-level measuring device is functionally able. Thus, the fill-level measuring device detects, independently, whether it is functionally able, or whether an error is present, caused principally by device-internal disturbance signals. This offers, especially, a clear advantage as regards meeting safety standards for the field device.

A circuit includes a transmission channel that outputs a continuous-wave signal based on a reference signal, a transmit monitoring signal path that couples out a portion of the transmit signal as a monitoring signal, a test phase shifter that receives the reference signal and generates a phase-shifted signal based on a sequence of phase offsets applied to the reference signal, a phase mixer that mixes the phase-shifted signal and the monitoring signal to generate a mixer output signal including a plurality of direct current (DC) values, an analog-to-digital converter that samples the mixer output signal in order to provide a sequence of DC values; and a monitor circuit that applies a discrete Fourier transform (DFT) to the sequence of DC values to generate a plurality of DFT bins with corresponding DFT bin values, and generate compensated phase information of the transmission channel using at least two DFT bin values.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment receives a sliding window of measurements associated with a radar signal transmitted by the UE; determines that a user is within a threshold distance of the UE, wherein the threshold distance is determined to be a first distance when an energy measurement, associated with the radar signal, indicates an energy reduction satisfying a threshold energy reduction, or wherein the threshold distance is determined to be a second distance when the sliding window of measurements indicates an amount of energy variation satisfying a threshold amount of energy variation associated with the radar signal; and performs, based at least in part on determining that the user is within the threshold distance, an action associated with a communication signal of the UE. Numerous other aspects are provided.

A method for wirelessly synchronizing a radar detector to a radar transmitter includes wirelessly receiving a first instance of a frequency-modulated continuous-wave (FMCW) radar signal directly emitted by the radar transmitter, determining a frequency slope change event in the FMCW radar signal using the first instance of the FMCW radar signal and temporally synchronizing the radar detector to the radar transmitter based on the frequency slope change event. Determining the frequency slope change event may include generating a frequency slope monitoring signal. In some embodiments, generating the frequency slope monitoring signal comprises mixing the first instance of the FMCW radar signal with a second instance of the FMCW radar signal. The second instance of the FMCW radar signal may be a reflected instance or a locally delayed instance of the first instance. A corresponding apparatus, computer readable medium and system are also disclosed herein.

According to an aspect, method in a radar receiver system comprising, receiving a radar signal reflected from a target on a plurality of antennas, wherein the radar signal is a frequency modulated continuous wave (FMCW) signal comprising plurality of chirps, extracting a plurality of range bins from the radar signal, generating a plurality of reference angles and a plurality of reference velocities from a plurality of reference parameters, determining a plurality of reference weights from the plurality of reference angles and plurality of reference velocities, filtering the radar signal with the filter weights set to equal to the plurality of reference weights.