贴片-网栅级联二阶宽带带通频率选择表面设计

Design of Second-Order Wideband Bandpass Frequency Selectrive Surface with Patch-Grid Cascaded

采用贴片谐振型与网栅感性型单元级联组合的方法,设计了一款二阶宽带带通频率选择表面(FSS),在0°~45°入射角范围内,通带为8.0~12.6 GHz,覆盖X波段,平均插入损耗小于1 dB。该结构由两层贴片型单元阵列和一层感性金属网栅级联组成,优化确定的FSS单元尺寸为0.136 λ×0.136 λ(λ为工作波长)。设计的FSS单元为小型化对称结构,采用等效电路法和全波电磁仿真,对该FSS结构的工作机理和TE/TM极化波在不同入射角的传输频率响应进行分析。研究结果表明在0°~60°入射角范围内传输频响具有较好的角度稳定性和极化一致性,所设计的单元级联结构的层间耦合小,弱化了单元对齐的影响,其对带通曲面天线罩设计具有应用价值。

In this paper, a second-order wideband bandpass frequency selective surface(FSS) is proposed by combining patched and inductive grid units. In the range of 0°-45° incident angles, the passband is 8.0-12.6 GHz, which covers the X-band. The structure is composed of two-layer patch unit array and one layer of inductive metal grid. The optimized FSS cell size is 0.136 λ×0.136 λ(λ is the working wavelength). The designed FSS unit has a miniaturized symmetrical structure. The operating mechanism of the proposed structure and the transmission frequency response of TE/TM polarized wave at different incident angles are analyzed by using the equivalent circuit method and full wave electromagnetic simulation. The results exhibit that the transmission frequency response has good angular stability and polarization consistency in the range of 0°-60° incident angles. The cascaded element structure has small interconnection between the adjacent layers, which weakens the effect of element alignment, and has application vaule for the design of bandpass curved radome.