Research And Design Of 77GHz Microstrip Array Antenna

As the number of automobiles increases sharply,traffic accidents are more and more frequent.How to improve the safety of vehicles and reduce traffic accidents is a hot spot for domestic and foreign manufacturers.Millimeter wave radar has the advantages of low cost and all-weather operation.In this paper,the 77GHz microstrip array antenna suitable for vehicle radar is studied.The short range radar array antenna,the long range radar array antenna and the phase controlled radar array antenna are designed respectively.Firstly,the basic knowledge and analysis method of microstrip antenna are introduced,and the principle of array antenna is analyzed,which provides a theoretical basis for the antenna design below.Secondly,the Chebyshev synthesis method is studied,and the 1×8 and 1×12 small linear arrays are designed as transceiver antennas.The simulation results show that the gain of the receiving antenna is 15.3dB,the sidelobe level is lower than-24dB,S₁₁=-25dB and the bandwidth of S11<-10dB is 1.4 GHz;the transmitting antenna gain is 17.1 dB,and the sidelobe level is lower than-24dB,S₁₁=-31dB and the bandwidth of S11<-10dB is 1.4 GHz;.After the antenna layout and test,the causes of the deviation of the test results are analyzed,and the design is improved.The improved transmit antenna gain is 14.5dB and the sidelobe level is less than-20dB,meeting the design requirements.Thirdly,the Taylor synthesis method suitable for large array is studied,and a new power divider is proposed to realize arbitrary power fraction by loading impedance converter at each output port.The design of 10×16 microstrip array antenna and 6×17 microstrip comb array antenna is completed.The simulation results show that the gain of 10×16 array is 26.2dB.The sidelobe level is lower than-20 dB,S₁₁=-19dB and the bandwidth of S11<-10dB is 1.4 GHz;The gain of 2×16 array is 19.6dB.The sidelobe level is below-20dB,S₁₁=-23.6dB and the bandwidth of S11<-10dB is 1.5 GHz;The gain of 6×17 comb array is 22.9dB,and the sidelobe level is below-20dB,S₁₁=-25dB and the bandwidth of S11<-10dB is 1.4 GHz.The 10×16 array gain is 21.7dB and the sidelobe level is less than-20dB,meeting the design requirements.Finally,the principle of low sidelobe phased array antenna is studied.On the premise of grating lobe suppression,a 1×4 linear array is used as a unit to form a phased array according to H-plane arrangement.The gain is higher than 18dB and the sidelobe level is lower than-15dB in±50 beam scanning range.