Research And Design Of Vehicle Antenna For Mobile Communication System

In order to satisfy the needs of various communication services for automobiles,automobile antennas working in multiple bands are constantly emerging,which promote the development of multi-band antennas and miniaturized antennas.Based on the above research points,the automobile antennas are studied as follows:1.A two-branch vehicle antenna is designed for the requirement of mobile communication frequency band.The antenna is composed of semi-T monopole and semi-cone monopole,which are placed vertically on the metal plate.T-branch mainly works at low frequency,and cone-branch mainly works at high frequency.The cone-branch adopts tapered structure in order to improve the impedance matching of antenna and increase the bandwidth of antenna,the antenna can be miniaturized by cutting the antenna in half.Finally,the antenna is processed and measured and the two operating bandwidths are 720MHz-960 MHz and 1.6GHz-4GHz.The antenna can cover communication service bands,include AMPS,GSM,LTE and 5G.The size of antenna is 30mm*70mm.2.According to the size of shark fin shell,a three-branch vehicle antenna is designed.The antenna consists of three monopoles and a ground plane.Through gradient technology,the current is smoothed,the bandwidth is improved.By adding capacitive structure and loading slots in order to improve impedance matching.The antenna is processed and measured and the frequency band with reflection coefficient of-10 dB is 0.85GHz-1GHz and 1.69GHz-3.81 GHz,which can cover many communication bands,include GSM,LTE and 5G.The size of antenna is 25mm*70mm.3.According to the size requirement of vehicle console,a built-in vehicle MIMO antenna is designed.The antenna system consists two identical PIFA antenna elements,an L-shaped decoupling structure and a ground plane.The antenna can work in multiple bands by loading slots,the height of vehicle console is utilized by using PIFA antenna in order to reduce the size of antenna,the antenna bandwidth is extended by coupling feeds,and the antenna coupling is reduced by polarization diversity and L-type isolation structure.Finally,the antenna is processed and measured and the band with reflection coefficient of-6dB covers GSM,LTE and 5G bands.The size of the antenna system is 100mm*40mm.