A vehicle includes a plurality of transmitters of a code division multiple access (CDMA) radar system to simultaneously transmit a frame of transmit signals. A first time duration between transmissions of a first pair of sequential ones of the transmit signals is linearly increased to a second time duration between transmissions of a second pair of sequential ones of the transmit signals. The vehicle also includes a receiver of the CDMA radar system to receive reflected energy resulting from reflection of one of more of the transmit signals of one or more of the plurality of transmitters by an object. A controller processes the reflected energy to obtain information about the object and to control an operation of the vehicle based on the information.

A system includes a local oscillator (LO) signal generation circuit, a receiver (RX) circuit, and a calibration circuit. The LO signal generation circuit generates an LO signal according to a reference clock, and includes an active oscillator that generates the reference clock. The active oscillator includes at least one active component. The RX circuit generates a processed RX signal by processing an RX input signal according to the LO signal. The calibration circuit checks a signal characteristic of the processed RX signal by detecting if a calibration tone exists within a receiver bandwidth, set a frequency calibration control output in response to the calibration tone being not found in the receiver bandwidth, and output the frequency calibration control output to the LO signal generation circuit. The LO signal generation circuit adjusts an LO frequency of the LO signal in response to the frequency calibration control output.

A method for testing at least one reception path in a radar receiver is provided. The reception path contains a mixer and a downstream signal processing circuit. The method includes injecting a test signal into the radar reception path so that at least a first test tone having a first test tone frequency in a passband of the downstream signal processing circuit and a second test tone having a second test tone frequency outside the passband are present on the radar reception path downstream of the mixer; and determining a characteristic of the radar reception path based on a first characteristic of a baseband signal at the first test tone frequency and a second characteristic of the baseband signal at the second test tone frequency.

A method for testing a distance sensor includes: receiving an electromagnetic free-space wave as a receive signal; generating a simulated electromagnetic reflection signal therefrom; shifting a reflection frequency of the reflection signal by a Doppler frequency smaller than a signal bandwidth of the receive signal; converting the receive signal into a first work signal having a first work frequency smaller than a receive frequency of the receive signal; converting the first work signal into a second work signal having a second work frequency, wherein the difference between the first and second work frequencies is at least as large as the signal bandwidth plus the Doppler frequency; converting the second work signal into a third work signal having a third work frequency that corresponds to the first work frequency shifted by the Doppler frequency; increasing the third work signal by the conversion frequency; and radiating the third work signal.

A radar target simulator with no lower target distance limitation and continuous distance emulation is provided. Said radar target simulator comprises a receiving unit configured to receive a radar signal from a radar under test and to provide a corresponding receive signal, and a ramp slope estimating unit. In this context, the ramp slope estimating unit is configured to track the ramp slope of the radar under test on the basis of the receive signal.

The present disclosure relates to a method for FMCW-based measurement of a distance of an object located in a waveguide, as well as a corresponding distance measurement device that, in particular, may be used for fill-level measurement in surge pipes or bypass pipes of containers. The method is based upon the fact that the transmission signal that is typical in FMCW is not ramp-like, and thus is emitted with constant frequency modulation. Rather, according to the present disclosure, a curvature of the frequency ramp is set to be at least approximately proportional to the frequency dependency of the propagation velocity of the transmission signal in the waveguide. The distortion effect is thus compensated for in that the propagation velocity of the transmission signal in waveguides is not constant, but, rather, decreases with falling transmission frequency.

Method and systems for object detection using a radar module are disclosed. Frames of range and doppler data are received from a radar module at sample time intervals. Doppler zero slice data is extracted from a current frame of the range and doppler data. A prediction of doppler zero slice data is maintained. The prediction of doppler zero slice data is based at least partly on doppler zero slice data from a previous frame of range and doppler data. Standard deviation data is determined based at least partly on prediction error data. The prediction error data relates to a difference between the prediction of doppler zero slice data and the doppler zero slice data. An object detection output is determined based on a comparison of the standard deviation data and an object detection threshold.

A radio frequency (RF) circuit includes an input terminal configured to receive a reception signal from an antenna; an output terminal configured to output a digital output signal; a receive path including a mixer and an analog-to-digital converter (ADC), wherein the receive path is coupled to and between the input and output terminals, wherein the receive path includes an analog portion and a digital portion, and wherein the ADC generates a digital signal based on an analog signal received from the analog portion; a test signal generator configured to generate an analog test signal injected into the analog portion of the receive path; and a digital processor configured to receive a digital test signal from the digital portion, the digital test signal being derived from the analog test signal, analyze a frequency spectrum of the digital test signal, and determine a quality of the digital test signal.

Disclosed is a method and a corresponding distance-measuring device for measuring a distance to an object using FMCW radar. The method includes the frequency-dependent determination of the amplitude of the radar signal, i.e. the frequency response in the output path and in the input path of the distance-measuring device. The standard windowing of the evaluation signal can be corrected using a correction factor dependent on the frequency responses. Thus the frequency dependence of the radar signal is compensated independently of device-internal or external interferences by adapting the window function. The result is more accurate and reliable distance measurement using FMCW radar. Because the distance can be determined by the disclosed method very accurately and without distortion, it is advantageous to use the distance-measuring device as a fill-level measuring device to measure the fill level of a filling material in a container.

A method for testing at least one reception path in a radar receiver is provided. The reception path contains a mixer and a downstream signal processing circuit. The method involves injecting a test signal into the reception path, so that at least a first test tone having a frequency in a passband of the signal processing circuit and a second test tone having a frequency outside the passband are present on the reception path downstream of the mixer. Further, the method involves tapping off a baseband signal, generated by the signal processing circuit, from the reception path, the baseband signal being based on the test signal.