A Reduced Size Planar Grid Array Antenna for Automotive Radar Sensors

A new configuration of a planar grid array antenna for automotive radar applications operating in the 77-81 GHz frequency band is introduced. The proposed array is based on miniaturized loop elements, which are designed to maintain the mutual interelement distance along the azimuthal plane to less than half free-space wavelength, thus allowing a better scanning performance in the final radar system. Moreover, to enhance the gain bandwidth performance, the antenna adopts multiresonant cells realized using variably dimensioned radiation elements. The proposed design was validated experimentally and it is fully compliant with multichannel monolithic microwave integrated circuits (MMICs) designed for automotive radar sensor applications.