Method for calibrating a MIMO radar sensor for motor vehicles

A method for calibrating an antenna diagram of a multiple input, multiple output (MIMO) radar sensor having Ntx transmitting antenna elements and Nrx receiving antenna elements, comprising:

• before commissioning of the radar sensor:
• storing an antenna diagram that associates with each of a plurality of several angles θ a respective control vector a(θ) that is made up of a transmitting control vector atx(θ) and a receiving control vector arx(θ);
• after commissioning:
• performing a radar measurement to localize an object;
• checking whether the localized object is a single target or a multiple target;
• if the localized object is a single target:
• performing a single input, multiple output (SIMO) measurement with each of the transmitting antenna elements;
• estimating the angle θ of the object based on the measurement results;
• calculating a first comparison variable, dependent on the components of the transmitting control vector atx(θ), for each transmitting antenna element;
• calculating a second comparison variable, dependent on the results of the SIMO measurements, for each transmitting antenna element;
• and
• correcting the transmitting control vector atx(θ) on the basis of a known relationship between the first and second comparison variables for each transmitting antenna element.