Research And Design Of Millimeter Wave Antenna Array Based On MIMO Radar

Millimeter wave MIMO radar has been widely studied.With the development of technology,the resolution of MIMO radar is becoming higher and higher,which makes the design of MIMO array particularly important.This article is mainly about the design of MIMO array,in order to design MIMO array with higher resolution.Firstly,a series-fed microstrip antenna which can be used in 77 GHz millimeter wave MIMO radar system is studied.According to the requirements of the actual MIMO radar system,a series-fed microstrip antenna is designed.The designed antenna operates at76-78 GHz,with gain of about 11 d B,azimuth beamwidth of about 76°,pitching beamwidth of about 31°,and sidelobe level of less than-17 dB.Then,according to the requirements of MIMO radar imaging system,a uniform linear MIMO array design method is presented.According to the resolution requirements of actual MIMO radar imaging,a 12 Tx 16Rx MIMO array is designed,and it is applied to the 77 GHz MIMO radar system cascaded by four MMIC chips.The equivalent virtual array of the designed MIMO array is an array uniform linear array with 192 elements and array spacing d is set as 0.54λ.The resolution of the MIMO array is 0.55°,but the range of angle measurement without fuzzy is reduced to-67.8°～67.88°.The practical tests show that the12 Tx 16Rx MIMO radar can achieve a high angular resolution of 0.55°.Finally,in order to further improve the resolution of MIMO array,a design method of sparse linear and sparse planar MIMO array based on genetic algorithm is proposed.With this design method,the MIMO array can be sparsely designed according to the specific resolution requirements of millimeter wave radar,and the highest resolution can be achieved with as few antenna elements as possible.For the sparse linear MIMO array design method,a design example of 9Tx 12 Rx MIMO array is presented and the simulation results show the resolution of designed MIMO array is 0.5°.According to the sparse planar MIMO array design method,a 9Tx 12 Rx MIMO array with the azimuth resolution of 0.8° and pitch resolution of 1.8° and a 6Tx 8Rx MIMO array with the azimuth resolution of 1° and pitch resolution of 2° are designed.Furthermore,the DOA estimation simulation of the 6Tx 8Rx MIMO array is carried out,and it is applied to the actual MIMO radar system based on two MMIC chips to test the relevant performance.