Design And Research Of Microstrip Array Antenna For Millimeter Wave Radar

Microstrip patch array antennas are mostly used in automotive millimeter-wave radars,mainly because of their small physical size,low profile,and easy integration.In order to improve the performance of the vehicle-mounted millimeter-wave radar,a linearly polarized array antenna and two circularly polarized array antennas are designed in this thesis.The series-type feeding network is used in the array design,which saves the size and space.In this thesis,three array antennas are designed at 62GHz,the main tasks are as follows:1)A linear cascading linearly polarized microstrip array antenna is designed,which is composed of multiple metal patch units in series.The patch width taper method is adopted to reduce the side lobe level to-33.5d B.The impedance bandwidth of the array antenna is 4.4GHz.2)A MIMO circularly polarized serial array antenna is designed.The radiating element of the array antenna is composed of a square metal patch,and the circular polarization design is completed by adopting a square chamfer on the diagonal of the patch.The array antenna includes three transmit and four receive sub-arrays.Among them,the transmitting and receiving arrays adopt right-handed and left-handed circular polarization designs respectively to realize polarization isolation.The structure of the array antenna is simplified,and the size of the transmitting array antenna is11.42×11.38 mm~2,and the size of the receiving array antenna is 11.42×8.89 mm~2.The-10d B impedance bandwidth of the array antenna is 58.86-65.15GHz,and its 3d B axial ratio bandwidth is59.9-64.1GHz.3)A circularly polarized serial comb-type array antenna is designed.The radiating element of the array antenna is composed of a square metal patch.The center of the patch adopts a rectangular cut angle and then rotates 45 degrees to complete the circular polarization design.The array antenna is right-handed circularly polarized with a size of 9.54×13.18 mm~2,its-10d B impedance bandwidth is 58.06-64.50GHz,and its 3d B axial ratio bandwidth is 59.9-64.1GHz.