方向图可重构的平面准八木天线的设计与实现

Design and Implementation of Radiation Pattern Reconfigurable Planar Microstrip Antenna

通信系统的快速发展对天线的性能提出了更高的要求,方向图可重构天线是天线家族中重要组成部分之一,应用十分广泛。文中利用HFSS软件对方向图可重构的平面准八木天线进行了设计与实现,天线结构基于传统的偶极子天线以及八木天线并采用差分馈电,主天线振子置于介质板的两侧,在地板一侧的振子臂通过PIN二极管开关与地板相连,馈电一侧的阵子臂通过PIN二极管开关与馈电相连。通过组合控制二极管的开关状态即可控制天线单元的工作状态从而实现天线方向图可重构的目的。结果表明天线的回波损耗在中心频点出达到-25d B,-10d B带宽为约为400MHz,相对带宽为13%,天线在主辐射方向的增益达到约4.5d B,该天线能够实现4个方向的扫描,具有良好的方向性。

The development of wireless communication system has raise higher demand on the performance of antenna, the radiation pattern reconfigurable antenna is widely needed in wireless communication system. In this paper the radiation pattern reconfigurable microstrip antenna has been designed and realized. This structure is based on traditional dipole antenna and Yagi antenna. According to dif- ferential feeding theory, the two arms which consist of the driven dipole are loaded on each side of substrate. A PIN diode switch is loaded between the ground and each driven dipole arm a PIN diode switch is loaded between the feed and the other driven dipole arm. The antenna radiation pattern can be reconfigurable by combination controlling the diode switch state. The result shows that the return loss is -25dB at center frequency. -10dB bandwidth is about 320MHz, relative bandwidth is about 13%. The maximum gain at main radiation direction reaches 3dB. This reconfigurable antenna has good direetivity with the scanning function of eight direction and can be applied in wireless communication system.