高功率宽频比C/X双频反射阵列天线设计

Design of high power wide frequency ratio C/X dual-band reflectarray antenna

为了满足高功率微波系统对宽频比双频辐射天线的研究需求,提出了一种可工作在C/X双频段的高功率圆极化反射阵列天线。天线单元采用介质埋藏的贴片单元形式,贴片部分由外圈的椭圆环贴片嵌套内圈的椭圆贴片组成,分别实现低频(C波段)和高频(X波段)的辐射。这种嵌套式的单元形式使得天线可以实现较宽的频比,同时由于单元采用无突变结构且单元被埋藏在介质中避免了三相点的出现,从而具有较高的功率容量。高低频段的两种贴片都采用绕轴旋转的方式来调节反射相位,可以在反射损耗较小的基础上满足360°的反射相位调节。基于以上双频辐射单元设计了一个口径尺寸为400 mm×400 mm的20×20矩形栅格排布反射阵列天线,设计结果表明天线在4.3 GHz下的增益为22.2 dBi,口径效率为40.2%,常压空气中的功率容量为10.4 MW;在10.4 GHz下的增益为29.9 dBi,口径效率为40.5%,常压空气中的功率容量为12.2 MW。该天线高低工作频率的频比达到2.4,且具有高效率和高功率容量的特点。

To meet the research demand of high-power microwave system for wide frequency ratio dual-band antenna,this paper proposes a high-power circularly polarized reflectarray antenna that can work in C/X dual-band.The antenna unit adopts the form of substrate buried patch,and the patch part consists of an elliptical ring patch nested with an elliptical patch in the inner to realize the radiation of low frequency(C-band)and high frequency(X-band)respectively.This nested cell form enables the antenna to achieve a wide frequency ratio,at the same time,because the cell has no abrupt structure and it is buried in the substrate to avoid the emergence of triple junction,it has a high power capacity.The two patches of high and low frequency bands rotate around the axis to adjust the reflection phase,which can meet the reflection phase adjustment of 360°on the basis of small reflection loss.Based on the above dualband radiation unit,design and optimization of a 20×20 rectangular grid reflectarray antenna with an aperture size of 400 mm×400 mm are made.While the antenna works at 4.3 GHz,the gain is 22.2 dBi,the aperture efficiency is 40.2%,and the power capacity is 10.4 MW in air condition.At 10.4 GHz,the antenna has a gain of 29.9 dBi,an aperture efficiency of 40.5%,and a power capacity of 12.2 MW in air condition.the frequency ratio between high and low working frequencies of the antenna reaches 2.4,and it has the characteristics of high efficiency and high power capacity.