LCP柔性HMSAFSIW带通滤波器设计与实现

Design and implementation of LCP flexible HMSAFSIW bandpass filter

基片集成波导(SIW)滤波器因具有高品质因数(Q值)、便于平面集成的优点,受到研究人员的青睐。但是,随着频率的不断提高,SIW基板的介质损耗会不断升高。为了克服以上难题,并且进一步缩小滤波器体积,基于柔性LCP基板,设计并实现了一款半模空气隙填充的基片集成波导(HMSAFSIW)带通滤波器。由于HMSAFSIW传输结构中空隙的引入,其介质损耗会大大降低。同时,通过在HMSAFSIW谐振腔结构中引入金属通孔和槽线结构,使滤波器的带外抑制得到较大幅度的改善。对滤波器样品进行了平坦和弯曲测试。结果表明,该滤波器中心频率为11.5 GHz,相对带宽为14%,其在平坦和弯曲情况下的微波特性一致。

Substrate integrated waveguide(SIW)has attracted much attentions of researchers due to its higher quality factor(Q-factor)and easy planar component integration.However,the dielectric loss of SIW becomes worse at higher frequency.To overcome above problems and reduce the size of the filter,a half mode slab air filled substrate integrated waveguide(HMSAFSIW)bandpass filter was proposed and implemented on flexible LCP substrate.The dielectric loss of the HMSAFSIW transmission structure was greatly reduced due to the air slab in the substrate.Meanwhile,the stopband suppression of the filter was greatly improved by introducing metal through hole and slot line loaded into HMSAFSIW resonator structure.The measured results show that the filter has a central frequency of 11.5 GHz with a relative bandwidth of 14%.The microwave performance remains the same when the substrate bent.