一种波束可调的平面印刷八木天线

A Planar Printed Yagi Antenna with Adjustable Beam

利用八木天线的高定向性,设计了一种6个方向波束可调的平面八木印刷天线.天线的主辐射振子采用新颖的梯形结构来增加工作带宽,将其两臂置于介质板两侧,仅需在地板上的每个辐射振子臂与地板之间加载一个PIN(positive-intrinsic-negative)二极管开关,就可控制天线单元的工作状态,即天线的辐射方向,而无需专门设计偏置电路.测试结果与仿真结果吻合较好,研究结果表明天线输入端反射系数小于-10dB带宽为400MHz.在30°,90°,150°,210°,270°,330°等主辐射方向上可重构天线增益为7.5 dB,半功率波瓣宽度小于60°.该天线能够实现6个不同方向的扫描,具有良好的方向性,可用于小基站或其他无线通信系统中.

Based on the high directivity of Yagi antenna, a planar Yagi printed antenna with six adjustable beams is designed. In order to increase the bandwidth, a tie type struc-ture is used as the driven dipole, of which the two arms are located on the opposite side of the substrate. Only one PIN （positive-intrinsic-negative） diode switch is loaded between the ground and the driven dipole arm on the ground to control the antenna element with its radiation direction having no extra bias circuits required. The measured results well match the simulation, and show that the bandwidth of the return coefficient below-10 dB is 400 MHz, gain of the reconfigurable antenna is 7.5 dB on the main radiation directions of 30？, 90？, 150？, 210？, 270？and 330？, and the half power beam width of each direction is be-low 60？. This reconfigurable antenna with the scanning function of six directions and good directivity can be applied to small base stations or other wireless communication systems.