Study On Simulation Of Electromagnetic Character Of Vehicle Antennas

With the development of automobile industry and increasing request to the automobile's security, comfortableness and functionality, more and more apparatuses for radio, wireless communication, satellite and radar system are used in vehicles. Many antennas were used for vehicle with these apparatuses. Complicated car body will affect electromagnetic characteristic of antennas installed on it. There will be interference between antennas. Antenna is also a interferential source which can produce complicated electromagnetic condition to affect the electromagnetic compatibility of devices in vehicles. How to estimate and forecast these affections on vehicle antennas and how to design an efficient vehicle antenna are important issues in vehicle engineering.Experiment and testing are used for research of vehicle antennas commonly. With the development of computer technology and electromagnetic numerical computation, the numerical simulation technology becomes a useful method. This method has many excellences such as fast compute speed, low cost, convenient for the parameter's revise, high success rate for prediction. It can find potential problems at initial stage of systematic research. So it is a good engineering method which has much economic benefitsIn this paper, the numerical simulation technology was used for the research of vehicle antennas. The main contents are as follows:1. The base principle of finite integral method (FIT) was studied detailedly. The Maxwell's grid equations and the solution of Maxwell's grid equation in time domain were derived. The simulation excitation, the numerical stability and the boundary condition were also researched.2. The radiation principle and electrical parameters of antennas were researched, the analytic method for electrical net ports was used to research the coupling between antennas. The electrical parameters of antenna and the coupling degree between antennas on different metallic carrier were simulated to analyze the variational rule.3. A full-scale car model with details which can be used for simulation was constructed. The method for simplifying models and the fast simulation method were researched too. The electrical parameters of single whip antenna on vehicle and the electrical field produced by antennas was studied. The coupling degree between vehicle whip antennas was also simulated and analyzed.4. A test scheme was designed to measure antenna terminal voltage produced by some vehicle interferential source in semi-anechoic chamber.The disturbance between antenna and interferential source was analysed by test result.5. Based on the study of PIFA antenna's principle, the parameters of PIFA antenna was simulated. Then a low profile dual-frequency PIFA antenna was designed. At last the structure of this antenna was optimized to realize the antenna's use on the vehicle.