一种低剖面轻量化星载薄膜C/X双频反射阵列天线

A Low-Profile Lightweight Spaceborne Thin-Film C/X Dual-Band Reflectarray Antenna

摘要: 本文提出了一种用于卫星通信的轻型星载C/X双频段薄膜反射阵列天线，该天线设计在厚度为20 μm的聚酰亚胺薄膜上。该双频段反射阵列单元由一个工作在C频段的单元和四个工作在X频段的相同单元组成，所有单元均设计在同一层上。C频段单元为2 × 2网格状结构，由四个非封闭矩形框架构成。四个X频段单元分别部署在C频段单元的每个网格中，每个X频段单元由一个圆环和两个呈中心对称分布的弧形分支组成。由于采用了聚酰亚胺薄膜基板，该反射阵列天线的重量仅为0.57 kg/m²。此外，该天线具有低剖面，电尺寸为15.53 λ_L × 15.53 λ_L × 0.07 λ_L，其中λ_L为最大波长(对应于最低频率)。我们制作并测量了反射阵列天线的原型，其在4.6 GHz和9 GHz频率下分别实现了29.98 dBi和35.63 dBi的峰值增益、32.1%和30.8%的孔径效率以及10.9%和19%的带宽。

Abstract: In this paper, we present a lightweight spaceborne C/X dual-band thin-film reflectarray antenna for satellite communication, which is designed on a polyimide film with a thickness of 20 μm. The dual-band reflectarray unit consists of one element operating in C-band and four identical elements operating in X-band, which are designed on the same layer. The C-band element is a 2 × 2 grid-like structure composed of four non-closed rectangular frames. Four X-band elements are respectively deployed in each grid of the C-band element, each of which consists of a circular ring and two arc-shaped branches distributed in central symmetry. With the polyimide film substrate, the reflectarray antenna achieves a light weight of 0.57 kg/m². Furthermore, the antenna has a low profile with an electrical dimension of 15.53 λ_L × 15.53 λ_L × 0.07 λ_L, where λ_L is the largest wavelength (corresponding to the lowest frequency). A prototype of the reflectarray antenna is fabricated and measured, which reaches peak gains of 29.98 dBi and 35.63 dBi, aperture efficiencies of 32.1% and 30.8%, with bandwidths of 10.9% and 19% at 4.6 GHz and 9 GHz, respectively.