Research And Design Of Millimeter Wave Radar Planar Array Antenna

Along with the development of various application requirements and advancement of technology,the design of modern radar systems gradually develops towards mininaturization and high resolution,especially for radar antenna systems.The planar array antenna,composed of waveguide slots,microstrip patches,printed oscillators,or non-standard size horns,has gradually become the preferred form of radar antennas,which has the benefit of compact structure,small size,low profile,and high efficiency.In addition,in order to meet the demands of small size and high resolution,the operating frequency of radar systems is getting higher,such as millimeter wave and sub-millimeter wave frequency bands,which also brings many challenges to the design of radar antennas.In this paper,a planar array antenna,designed by a new type of composite structure horn array element,is presented in W band.And combined with a non-standard size horn antenna element and an array feed network,this antenna has achieved the high gain and high radiation efficiency requirements.The main work is as following three parts:1.Planar array element design.By analyzing the characteristics of several types of array elements: microstrip antennas,waveguide slots,and open-end waveguides?horns?,it is determined that non-standard size horn is used as array elements;this paper a new type of composite structure horn array element with aperture of 1.7?₀×1.7?₀ is proposed.and four non-standard size horn antennas,excitated by a cavity,are combined to form an array element,which not only increases the spacing of antenna,but reduces the difficulty of designing the feed network and the overall processing difficulty of the array.2.Planar array antenna feed network design.According to the basic theory of the power divider and antenna element performance,the millimeter wave radar planar array antenna feed network is designed.There are sixty-four-way waveguide power dividers on the azimuth that the output power of each channel meets Taylor distribution,while there is an eight-way equally divided waveguide power on the pitch.The simulation results show that the return loss of the feed network is less than 19 d B,and the simulation value of the output power of the one-dimensional row port is basically consistent with the theoretical value.3.Planar array antenna design.A 2×2 array is firstly designed by a new type of composite structure horn array element and then tested.Through the comparison of simulation and test results,the design of the composite structure horn element and feed network continues to be optimized,providing the basis for the final design of 64×8 array elements millimeter wave radar planar array antenna.