基于3D打印技术的新型宽阻带电磁带隙封装屏蔽盒

Novel 3D printed electromagnetic band-gaps for cavity mode noise suppression in microstrip circuit packages

设计了一种基于3D打印技术的倒置蘑菇型电磁带隙（electromagnetic band-gap,EBG）封装屏蔽盒.该封装屏蔽盒能够有效抑制4.7～12.6GHz频率范围内的腔体噪声,与传统的金属柱型EBG封装屏蔽盒相比,所设计的倒置蘑菇型EBG的周期单元尺寸缩小了81%（0.216λ0×0.216λ0×0.187λ0,λ0 为自由空间中阻带中心频率所对应的波长）,其相对阻带带宽可展宽至91.3%.通过等效电路建模分析了倒置蘑菇型EBG的阻带下截止频率,并在此基础上提出了倒置雨伞型EBG结构,使得EBG结构周期单元的电尺寸进一步缩小了38.3%.最后,利用3D打印技术加工制造了所设计的倒置蘑菇型和倒置雨伞型EBG结构,并将具有2个直角拐角的简单微带线放置其中进行插入损耗测量.实验结果表明,在阻带频率范围内,所设计的EBG封装屏蔽盒的腔体噪声得到了有效抑制.

An inverted mushroom Electromagnetic Band-gap(EBG)structure based on 3Dprinting technique is proposed for cavity mode noise suppression in microwave circuit packages.Its dispersion diagram analysis shows that the cavity mode noise from4.7-12.6GHz can be effectively suppressed.Compared with the previous EBG(lid of nails)in the literature,the size of the unit cell of the proposed inverted mushroom EBG is reduced by 81%to 0.216λ0×0.216λ0×0.187λ0,and its fractional bandwidth of the stopband is enhanced to 91.3%.A 2-D equivalent circuit model is established to explain its Mode 1in the dispersion diagram.Then,another inverted umbrella EBG is proposed and the electric size of the unit cell is decreased by 38.3% without deteriorating the stopband.Finally,a simple microstrip line with two bends is fabricated for verifying the noise suppression performance.The measured result shows that the cavity mode noise in the stopband of the proposed two EBGs is suppressed and the insertion loss of the microstrip line is similar to that of the unpackaged one.