【摘要】 利用感性表面(金属栅格)与容性表面(间隔的金属环形贴片)之间的耦合机制制备了微型频率选择表面(MEF-SS)。依据传输线理论给出电感、电容近似公式,定性分析了MEFSS结构参数,采用全波分析矢量模匹配法计算了不同几何结构参数与耦合层电参数MEFSS的传输特性。通过镀膜与光刻法在500μm厚聚酰亚胺膜两侧以矩形排列方式制备了12个0.125λ集总电感单元与集总电容单元,利用自由空间法测试了240mm×240mm MEFSS样件的传输特性。结果显示,测试样件中心频点为14.636GHz,透过率为-0.382dB,-3dB,带宽为2.17GHz时,单元尺寸为0.125λ;当单元尺寸变小时,中心频点向高频漂移,其透过率下降;固定单元尺寸,中心频点随固定电感宽度、电容间隔和环形贴片宽度的增加而向高频漂移;耦合层厚度增加0.4mm,中心频点向低频漂移1.4GHz,且透过率降低2.6dB;相对介电常数由3.5变为2,中心频点向高漂移2.8GHz。结论显示,利用感性与容性表面耦合机制能制备单元尺寸为0.125λ的FSS,其具有微型化、宽通带和对入射波角度不敏感的特点。更多还原

【Abstract】 A Miniaturized-element Frequency Selective Surface(MEFSS) was fabricated based on the coupling mechanism between an inductive surface(metallic meshes)and a capacitive surface(wire patches).On the basis of the theory of the transmission line,the approximation formulas of the capacitance,the inductance were provided and the structural parameters of MEFSS were analyzed qualitatively.By using the vector modal matching method and the transmission characteristics of MEFSS with different geometry parameters and coupling layer electrical parameters were studied in this paper.Twelve lumped inductors and lumped capacitors were properly fabricated on the two side of a PI film by orthogonal arrangement,and the transmission characteristics of a MEFSS with a size of 240 mm×240 mm was tested by free space method.Results show that when the center frequency is 14.636 GHz,transmittance is-0.382 dB and the half transmittance bandwidth is 2.17 GHz at a TE 0° incidence.When the unit cell size is shorted,the center frequency drifts and the transmittance is decreased.The unit cell size is 0.125λ.When the unit cell size is fixed,the center frequency drifts as the increases of inductive widths,capacitance intervals and patch widths.Moreover,if the thickness of the coupling layer is increased by 0.4 mm,the center frequency lowly drifts by 1.4 GHz and transmittance is decreased by 2.6 dB.If the coupling layer relative permittivity is changed from 3.5 to 2,the center frequency highly drifts 2.8 GHz.It concludes that the FSS only with a size of 0.125 λ fabricated by coupling mechanism between inductive and capacitive surfaces is charaterized by miniaturization,wide pass-band and lower sensitive to the incident angle unit.更多还原