采用微控制电路加载技术控制超材料的等效介电常数和等效磁导率在不同时间的空间分布形式, 实现空间滤波器中心频率的可调.设计了一种方环缝隙结构超材料滤波器, 单元结构尺寸为18.5 mm×18.5 mm, 通过在单元结构上加载变容二极管实现X波段内的连续可调.当变容二极管电容值从0.15 pF增大到0.70 pF时, 仿真结果表明滤波器的中心频率从11.8 GHz逐渐减小到10.5 GHz, 工作带宽为16.3% (10.2~12.0 GHz), 通带内的回波损耗最小值为22 dB, 插入损耗最大值为0.6 dB.测试结果表明滤波器的中心频率从11.7 GHz逐渐减小到10.3 GHz, 工作带宽为17.2% (10.1~12.0 GHz), 且通带内的回波损耗最小值为25 dB, 插入损耗最大值为0.5 dB.

A tunable metamaterial filter is designed based on split-ring resonators (SRRs) in this paper. The metamaterial filter has a compact size of 15 mm×20 mm, and miniaturization is realized by using the SRRs. By loading tunable devices, the continuous operation of the filter is realized at X band (from 10.7 GHz to 12 GHz), the bandwidth is about 13%, the minimum return loss is 35 dB, and the maximum insertion loss is 0.37 dB. The results illustrate that the metamaterial filter shows the compact size, wide bandwidth and good band pass characteristics.

为了提高频谱资源的利用率，解决传统滤波器组体积大的问题，利用开口环结构的超材料具有高集成度的特性，设计了一款整体尺寸仅为15 mm×20 mm的滤波器.基于时域有限积分法分析了开口环结构滤波器的反射系数曲线与电磁参数之间的响应特性，通过在开口环缝隙处加载可调谐的二极管器件，实现了超材料滤波器在X波段(10.9~12 GHz)的连续可调，扩展了滤波器的工作频带.该可调谐超材料滤波器的工作带宽达11.0%，通带内回波损耗最小值为32 dB，插入损耗最大值为0.38 dB，具有高集成度、宽频带、通带内选频特性良好的特点.

This paper presents a compact triple-band bandpass filter based on metamaterials. The miniaturization is realized by the principle of phase compensation of metamaterial. Compared with the conventional half-wavelength filter, the metamaterial filter has a small size of 10 mm×10 mm. The triple-band bandpass filter performance has been validated by the electromagnetic simulation software of high frequency structure simulator (HFSS). The results illustrate that the filter is designed with center frequencies of 2.4 GHz, 5.1 GHz and 8.8 GHz, bandwidths of about 7.9% (2.31.2.50 GHz), 7.8% (5.0.5.4 GHz) and 7.4% (8.50.9.15 GHz), respectively, and it shows good band pass characteristics.

考虑材料的电磁屏蔽特性和可见光透过的矛盾, 设计了以铝/氧化铟锡(Ag/ITO)为周期的光子晶体薄膜以实现电磁屏蔽和可见光透过的兼容。首先根据电磁屏蔽和可视的双重需求, 优化了光子晶体的组份并对其性能进行了研究。接着采用磁控溅射方法制备了以Ag/ITO为周期的光子晶体薄膜, 并对光子晶体薄膜的屏蔽和可见光透光率进行了测试和分析。实验结果表明: 这种光子晶体薄膜在金属Ag总膜厚大于可见光趋肤深度而远小于微波波段趋肤深度时, 在可见光波段的最高透光率高达55%, 而在微波x频率段的屏蔽性能最高可达65 dB。通过结构设计, 使薄膜的可见光透光率曲线与人眼的敏感曲线相吻合。随着每个周期Ag膜层的厚度增加, 方阻相应降低, 微波屏蔽性能相应提高。随着周期数的增加, 薄膜的可见光透光率没有相应降低、屏蔽性能没有相应提高。设计的光子晶体薄膜在30 MHz~18 GHz较宽波段的屏蔽性能均大于40 dB。这种设计方法为材料的电磁屏蔽和可见光透明兼容开辟了一条新的技术途径。