Research And Design Of Reconfigurable Antenn

Owing to the significant advantages in realizing miniaturization and multi-function of wireless communication systems,reconfigurable antennas are currently a hot research direction in the antenna field.The pattern reconfigurable antenna can change the shape of pattern or radiation directions according to different application environments to meet different communication needs.In popular fields such as Wi Fi and 5G vehicle communication,the research and application of pattern reconfigurable antennas have developed rapidly,how to expand the beam width coverage and operating bandwidth of pattern reconfigurable antennas is one of the focuses of my current research.Based on the application requirements of pattern reconfigurable antennas,this paper mainly studies and designs two new types of pattern reconfigurable antennas.The specific contents are as follows:1.A wide-angle scanning array antenna is proposed,which is composed of eight pattern reconfigurable antenna elements,elements and array are both operate at 5.8 GHz.Each element consists of two substrate layers with a pair of parasitic metal patches loaded with PIN diodes on the upper substrate and a back cavity slot antenna based on SIW(substrate integrated waveguide)on the lower layer.It is able to control the on-off between the parasitic patch and the floor on the lower substrate layer by changing the state of the PIN diode,which deflect the antenna beam towards both sides of the slot with deflection angles coming to 60 ° and 44 °.Then arrange the element into a 1 × 8 weighed thinned array,where the amplitude and phase difference of each element’s excitation are individually controlled.The experimental results show that the array can scan its main beam from φ=– 80 ° to φ=80 °,and the average gain of the main beam within the scanning range can reach 11.68 d Bi.2.Based on the dipole element,a pattern reconfigurable vehicle antenna is proposed.The antenna consists of three parts: a radiation unit,a feed network,and a parasitic unit.The radiation unit consists of four identical arc dipoles,the feed network consists of four baluns,and the parasitic unit consists of four pairs of metal patches placed outside the arc dipole arm.By controlling the state of the PIN diode on the parasitic unit,four different modes with endfire radiation patterns can be obtained in the xoy plane.The simulation results show that the operating frequency band of the antenna is 3.3 GHz to 3.8 GHz,the impedance bandwidth of10 d B is 14.3%,the average gain of the four states within the bandwidth can reach 5.4 d Bi,the front to back ratio exceeds 12.5 d B,and the radiation efficiency exceeds 81%.The proposed antenna is suitable for 5G vehicle communication applications in wireless communication...