RELATED APPLICATION

This application claims priority under 35 U.S.C. § 119 to German Patent Application No. 102018106858.1, filed on Mar. 22, 2018, the contents of which are incorporated by reference herein in their entirety.

TECHNICAL FIELD

The present disclosure relates to the field of radar sensors, in particular to radar sensing techniques that allow interference detection and/or suppression.

BACKGROUND

Radar sensors can be found in numerous sensing applications in which distances and velocities of objects are to be measured. In the automotive sector, there is an increasing demand for radar sensors that may be used in so-called advanced driver-assistance systems (ADAS). Examples of an advanced driver assistive system are “adaptive cruise control” (ACC) and “radar cruise control” systems. Such systems may be used to automatically adjust the speed of an automobile so as to maintain a safe distance from other automobiles driving ahead. Other examples of advanced driver assistive system are blind-spot monitors, which may employ radar sensors to detect other vehicles in the blind spot of a vehicle. Particularly autonomous cars may use numerous sensors, such as radar sensors, to detect and locate various objects in their surroundings. Information about the position and velocity of objects in the area of an autonomous car is used to help navigate safely.

Modern radar systems make use of highly integrated radio frequency (RF) circuits which may incorporate all core functions of an RF front-end of a radar transceiver in one single package (single chip transceiver). Such RF front-ends usually include, inter alia, a local RF oscillator (LO), power amplifiers (PA), low-noise amplifiers (LNA), and mixers. Frequency-modulated continuous-wave (FMCW) radar systems use radar signals whose frequency is modulated by ramping the signal frequency up and down. Such radar signals are often referred to as “chirp signals” or simply as “chirps”. In case of linear chirp signals the term “LFM signals” is sometimes used, wherein LFM stands for “linear frequency modulation”. A radar sensor usually radiates sequences of chirps using one or more antennas, and the radiated signal is backscattered by one or more objects (referred to as radar targets) located in the “field of view” of a radar sensor. The backscattered signals (radar echoes) are received and processed by the radar sensor. The detection of the radar targets is usually accomplished using digital signal processing.

As more and more automobiles are being equipped with radar sensors, interference is becoming an issue. That is, the radar signal radiated by a first radar sensor (installed in one automobile) may intersperse to the reception antenna of a second radar sensor (installed in another automobile) and impair the operation of the second radar sensor.

SUMMARY

A method for use in a radar device is described herein. In accordance with some implementations, the method includes generating an RF oscillator signal which includes frequency-modulated chirps, amplitude-modulating the RF oscillator signal by a modulation signal, and transmitting the amplitude-modulated RF oscillator signal via at least one antenna. In some implementations, the method may further include receiving an RF signal that includes frequency-modulated chirp echo signals from a target object, down-converting the received RF signal into a base band using the RF oscillator signal for providing a base band signal, and processing the base band signal to detect information included in the modulation signal.

Furthermore, a radar device is described herein. In accordance with some implementations, the radar device includes an RF oscillator configured to generate an RF oscillator signal that includes frequency-modulated chirps, a modulator receiving the RF oscillator signal and a modulation signal and configured to amplitude-modulate the RF oscillator signal by the modulation signal. The radar device further includes one or more antennas configured to transmit the amplitude-modulated the RF oscillator signal and to receive an RF signal that includes frequency-modulated chirp echo signals from a target object, a mixer receiving the RF oscillator signal and the received RF signal and configured to down-convert the RF signal into a base band for providing a respective base band signal, and an analog-to digital converter configured to digitize the base band signal. A computing unit is configured to process the base band signal to detect information included in the modulation signal.

