Vehicle Shark Fin Antenna System

With the fast development of automotive industry,the related electric parts are also in a quite fast development period,vehicle antenna system is one of them.The new technology will overturn our knowledge of vehicle communication,Car2Car,autopilot and Intelligent Traffic,all of these are based on the antenna system,so it will be more and more important in the future.The glass antenna is one of them,which is lied on the glass,and its biggest advantage is saving space,but the assembly and development process would be more difficult.Due to the high cost,the Vehicle body antenna is not so popular.The shark fin antenna which is installed on the roof of a vehicle is also a kind of antenna receive system.It is made up of a base board and other antenna modules which you can add functions as you want.There are many advantages,like shorten the development period,very good for automatic and mass production,waterproof and dustproof,more stable and stronger but low cost,easily recognized.For this design,firstly we need to study the international standard of Road Vehicles-Environmental Condition and test for electronical and electronic equipment,find out the environmental and EMC requirement,choose the right components based on the requirements,and then take the technical regulation of a vehicle manufacture for reference to make the design.Based on the theories of PCB antenna,Snake-shaped line to form a kind of helical antenna,it can meet the electronica performance requirement in a very limited space.For the GPS antenna,choose the ceramic antenna.Firstly,make a brief introduction of its structure and characteristics.Then analyze the modal-expansion cavity models,by using single-feed point method to make the fine tuning and finish the design.Follow the principle that noise figure is always prior to power transmit for LNA,use the software ADS to do the design and simulations of FM and GPS LNA.Since the GPS signal is so weak and easily disturbed,firstly,analysis the disturbance source,then figure out the solutions one by one.During the GPS LNA design,compare the two different design structure,finally finish the design and test it.At last,function test,reliability test and EMC test are performed to the system.All the results are PASSED.