Sparse antenna arrays for automotive radar

A method for selecting an arrangement of physical antenna elements and a randomly selected arrangement of virtual antenna elements for a proposed antenna array that is an optimum array arrangement selection for the proposed antenna array, wherein the method comprises:

• defining selected antenna array properties comprising at least one of dimension, available number of physical antenna elements, beam width, and maximum sidelobe level;
• calculating inter-element spacings and aperture lengths for the proposed antenna array as defined by a selected field-of-view (FOV) and beamwidth (BW), respectively;
• calculating reference full-grid element locations as defined by the selected FOV and BW;
• finding candidate element locations for a plurality of candidate element arrangements of the virtual antenna elements as defined by the selected antenna array properties and calculated inter-element spacing and aperture lengths;
• randomly selected a candidate element arrangement of virtual element locations from among a plurality of candidate element arrangements of virtual element locations that meet the defined selected antenna array properties and the calculated inter-element spacings and aperture lengths;
• calculating maximum sidelobe level (SLL) in the FOV for the randomly selected candidate element arrangement of the virtual antenna elements;
• randomly selecting additional candidate element arrangements of virtual element locations from among the plurality of candidate element arrangements of virtual element locations for an updated candidate element arrangement of the virtual antenna elements and recalculating the SLL for each updated candidate element arrangement of the virtual antenna elements until a selected candidate element arrangement of the virtual antenna elements is reached that meets the desired FOV and BW and has a resultant SLL that is below a threshold value;
• stopping the random selection of additional candidate element arrangements of virtual element locations of the virtual antenna elements and defining the selected candidate element arrangement as the selected arrangement of virtual antenna elements and physical antenna elements of the proposed antenna array when the selected candidate element arrangement of the virtual antenna elements results in a calculated SLL that is within a difference threshold value of an SLL value from the previous random candidate element arrangement of virtual element locations selection step, wherein the optimum array arrangement of virtual antenna elements and physical antenna elements is the selected arrangement of virtual antenna elements and physical antenna elements of the proposed antenna array;
• and
• providing for a radar system, an antenna array that comprises the selected arrangement of virtual antenna elements and physical antenna elements of the proposed antenna array.