Research On Key Technology Of 24GHz Automobile Anti - Collision Radar

With fast development of domestic economy, the number of automobiles is increasing rapidly, which causes further deterioration of road safety situation. Empolder of collision avoid radar, which provides early warning, will effectively prevent a lot of casualties and property loss. A low cost and small size collision avoid radar RF front end system is carried out in this thesis, in which the antenna and feed design is the research priority. Primary cov-erage is as follows:(1)The schema to design a low cost and small size RF front end is established after the comparison on characteristics of existing collision-avoid radar systems. The RF front end is made of a linear frequency modulated continuous wave based T/R module and a microstrip patch antenna array. The direction of target is measured by comparing phase delay between echo signals received by 2 receiving antenna arrays. The design scheme of the T/R module and the design parameters of the antenna are developed according to the system metrics.(2)A rectangular patch is chosen as basic structure for antenna element after appropriate dielectric plate is selected. Width of the rectangular patch is obtained which is 1.5 times as long as the patch length with detailed comparison. Two types of complete antenna elements are designed and simulated in HFSS on the basis of results above, with insert feed and non radiative edge feed respectively. Considering of limitation on size, compact parallel feed network is applied. After distribution of antenna elements are determined with estimation us-ing the principle of pattern multiplication, a holonomic antenna array model is completed in HFSS. Simulation and optimization results meet the requirements in schema.(3)The antenna array is measured and adjusted with PNA network analyzer. During the outdoor static simulation of front end system, an aluminum plate is placed to imitate a car. The range finding function works efficiently according to echo signals on oscilloscope, which also indicates the gain and beam width meet the requirements.The T/R module and transceiving arrays are completed, and meet the basic requirements in accordance with the phenomena in static simulation, validating the rationality and feasibil-ity of design method and process, providing references for further improvements and design of signal processing module.