Design Of The 24GHz Anti-collision Radar Antenna

In recent years,with the increasing prominence of road traffic safety,the auxiliary driving technology and the unmanned technology with the automobile anti-collision radar as the core have received the attention of major automobile manufacturers and technology enterprises.Millimeter wave radar due to its detection distance,high resolution and other advantages have also become a research hot spot in recent years.The micro-strip antenna is smaller and easier to integrate,and the price is also cheaper.Therefore,the millimeter-wave radar designed with the micro-strip antenna has a broad market prospect.Due to have shorter wavelength of the millimeter-wave radar and the influence of the hydrometeor in the air such as rain and fog on the electromagnetic wave,the detection accuracy of the linearly polarized antenna is lower.Compared with linear polarized waves,circularly polarized waves have the advantages of anti-rain and fog interference and suppression of multipath reflections.Therefore,this thesis starts from the demand of millimeter-wave automotive collision avoidance radar and according to the notice issued by the Ministry of Industry about the short-range vehicular radar frequency band,First of all,using the 0.508 mm Rogers5880 designed two opposite rotation of the circularly polarized micro-strip patch.Then based on the theory of the micro-strip array antenna,two circularly polarized micro-strip array antennas are designed.One is a wide beam micro-strip linear array antenna with the impedance bandwidth of 2.2GHz,the axial ratio bandwidth of460 MHz and the gain of 15.54 dB.And the test results are consistent with the simulation results.the other is a “one output two income” micro-strip planar array antenna.The transmitting antenna adopts the form of left-handed circular polarization,the simulation results show that the impedance bandwidth of the array antenna is 1.8GHz,the axial ratio bandwidth is 740 MHz,the gain is 21.2dB,the E-plane half-power lobe width is 11°,and the H-plane half-power lobe width is 20°.The receiving antenna adopts the form of right-hand circular polarization.The simulation results show that the impedance bandwidth of the array antenna is 2.3GHz,the axial ratio bandwidth of 680 MHz,the gain of 18.7dB,the E-face half-power lobe width of 11°and H-lobe width of 42°.The port of the antenna isolation greater than 30 dB.