Interference between automotive radars decreases the sensors' detection capabilities. It is possible to use digital beamforming (DBF) in multi-antenna systems to reduce the power received from certain directions of arrival (DoA). If digital beamforming is used to mitigate the effect of an interferer, it is shown that it is not sufficient to cancel the DoA of an interferer alone, if an I-Q mixer is not present. Additionally, a second DoA must be blinded out. A DBF system which performs this task is presented. Experimental and simulated results support the mathematical derivation and show possible improvements with DBF.