Research And Design Of Anti-collision Radar Array Antennas For Automobiles

With the rapid development of social economy and technology,and the continuous improvement of civil living standards,car ownership in our country is constantly increasing by year.At the same time,automobiles have become the major means of transportati on.Therefore,traveling safety and reducing traffic accidents have become the focus of society and the constant breakthrough of automobile manufactures.For anti-collision radar system as an active safety defense system in the fields of UAV and car driving,the advantages include effective prevention of traffic accidents and protection of personal safety.Among them,the millimeter-wave antenna is the key communication equipment in Anti-collision radar system.Due to its advantages of all-weather,high gain and strong directivity,the millimeter-wave antenna,has become the mainstream of the domestic automotive industry in recent years.However,due to high production costs,it can only fit in the high-end models,which can not be widely used in the low car.In this paper,the salient features of microstrip antennas are studied,such as easy integration,low manufacturing cost,easy common type,small size,etc.The purpose of this paper,in which the millimeter microstrip array antenna is applied to anti-collision radar system,is to achieve the results of low cost and high performance.Based on the above original intention,this paper designed three types of antennas.The main research contents are as follows:(1)The 2×10 array antenna with parallel feeding in the form of microstrip patch has been designed,and it works at 24 GHz.The unit adjusts the impedance of the antenna by adjusting the insertion depth and slot width of the microstrip line to achieve matching.The gain is increased by increasing the number of cells.The microstrip structure of the parallel unit is matched to 100? by a wavelength-impedance transformer.This antenna is fed to the antenna network from the back of the dielectric substrate via a coaxial probe.And it achieved the following indicators which is higher than the subject indicators,bandwidth of the antenna is 1.1GHz(bandwidth of the subject indicator is 500MHz),gain of the antanna is 20 d Bi(gain of the subject indicator is 20 d Bi),narrow beam width of the antenna is 8°(beamwidth of the subject indicator is less than 10°).(2)The 2 × 10 array antenna with series feed in the form of microstrip patch has been designed,and it works at 24 GHz.The advantage is that the series feed owns a compact structure,and reduces line losses.Also it is easy to achieve miniaturization and mass production.In order to meet the performance requirements of low sidelobes,it's amplitude weighting is achieved by tapering the current amplitude.The size of the patch unit is set by the Chebyshev polynomialcoefficient.By reducing the number of H-plane microstrip arrays,the main lobe width is reduced.And it achieve 180° phase compensation by the U-type device.And it achieved the indicators as follows,the bandwidth of the antenna is 0.62 GHz,gain of the antenna is19.44 d Bi,narrow beamwidth of E-plane is 9°.Basically,it meets the design specifications.The gain of the antenna can achieve 20 d Bi through the fine-tuning structure.(3)A 4×15 array antenna with series feeding in the form of microstrip patch was designed with a working frequency of 77 GHz.The unit size of patch was designed by Chebyshev polynomial and Taylor formula to achieve a good radiation distribution.The structure of the design is based on the SIW design technique,which translates into microstrip structure and improves fault tolerance through vertical conversion.And it achieved the following indicators which id higher than the subject indicators,the bandwidth of the antanna is 1.25GHz(indicator of the antenna is 1.2GHz),the half-power beamwidth of E-plane is 6°,sidelobe suppression ratio is greater than 20 d B(indicator of the antenna is greater than 18 d B).The above data shows that the designed antenna can meet engineering applications,and it can be used for mass production to reduce costs so that automotive anti-collision radar system can be popular for personal safety escort.