Driver assistance device for a vehicle and method for operating a radar device

Abstract

The invention relates to a driver assistance device () for a vehicle (), which driver assistance device has a radar appliance () for determining measured variable (α, α, R, R) referenced to an object () that is external to the vehicle, wherein the radar appliance () comprises: at least a first and a second reception antenna (), each for receiving signals (S, S); a first down-converter (), which is coupled to the first reception antenna () via a first reception path (), and a second down-converter (), which is coupled to the second reception antenna () via a second reception path (), for down-converting the received signals (S, S) into respective baseband signals (S, S); a control device () for determining the measured variable (α, α, R, R) using the baseband signals (S, S); and test means () for producing a local check signal (S) and for coupling the check signal (S) into the first reception path () and into the second reception path (), as a result of which the control device () receives the check signal (S) that has been down-converted by the first down-converter () as a first test signal (S) and the check signal (S) that has been down-converted by the second down-converter () as a second test signal (S). The control device () uses the test signals (S, S) to determine a frequency-dependent correction variable (δ()) for correcting the measured variable (α, α, R, R). The invention also relates to an appropriate method.