漏波天线中阻带的应用及抑制  

Utilization and Suppression of the Stopband in Leaky-Wave Antennas

作　　者：刘菊华 LIU Ju-hua(School of Electronics and Information Technology,Sun Yat-sen University,Guangzhou 510006,China)

机构地区：[1]中山大学电子与信息工程学院,广州510006

出　　处：《微波学报》2021年第2期1-5,共5页Journal of Microwaves

基　　金：国家自然科学基金(61771497);广东省基础与应用基础研究基金(2020B1515020053);广东省自然科学基金(2015A030312010)。

摘　　要：周期性结构会引入阻带。有些阻带对有些漏波天线有用,如可用于抑制某些不需要的传播模。但阻带对大部分周期性漏波天线是不利的,如边射阻带使得主波束在边射方向不能连续扫描。文中讨论了周期性结构阻带在漏波天线中的应用及抑制。给出了一个阻带应用实例:微带漏波天线一般工作于EH1模,在激励其EH1模时往往会激发不希望的EH0模,在微带漏波天线上加载周期性短路过孔产生EH0模的阻带,利用该阻带可有效抑制EH0模的传播,从而使得天线反射系数降低,增益增大且平稳。文中介绍了三种方法可完全抑制周期性漏波天线边射阻带:单元非对等双辐射元、短路过孔匹配以及渐变半波长传输线。通过完全抑制边射阻带,周期性结构漏波天线的主波束可从后向通过边射连续扫描到前向,其主波束连续扫描范围得到了有效扩大。这些方法可应用于基片集成波导、微带、同轴线等平面和非平面周期性漏波天线。A periodic structure usually features stopbands. Some stopbands are useful for some leaky-wave antennas. For example, it can be used for suppressing unwanted mode in a leaky-wave antenna. On the other hand, some stopbands are deleterious for most of periodic leaky-wave antennas. For example, the open stopband in a periodic leaky-wave antenna forbids the beam scanning continuously through the broadside direction. This paper discusses the utilization and the suppression of the stopband in leaky-wave antennas. An example for the utilization of stopband is given. The microstrip leaky-wave antenna typically works in the EH1 mode. When exciting the EH1 mode for the leaky-wave antenna, the unwanted EH0 mode is excited. By placing a set of periodic shorting vias along the center line of the antenna, a stopband in the EH0 mode is generated, which can be exploited for the efficient suppression of the propagation of the unwanted EH0 mode. With the suppression of the unwanted EH0 mode, the antenna exhibits a lower reflection coefficient, a higher and more stable realized gain. In addition, three methods are presented for the complete suppression of the undesired open stopband in periodic leaky-wave antennas, i.e., the unit cell of dual non-identical element, the shorting-via matching, and the tapered half-wavelength transmission line. With the complete suppression of the open stopband, the periodic leaky-wave antennas can have the main beam scanning continuously from the backward to the forward, and therefore the scanning range is greatly enlarged. The methods can be applied to planar and non-planar periodic leaky-wave antennas based on substrate integrated waveguide, microstrip, coaxial line, etc.

关 键 词：微带漏波天线 周期性漏波天线 基片集成波导 阻带 

分 类 号：TN822.6[电子电信—信息与通信工程]