基于孔耦合和枝节加载谐振器的双通带带通滤波器

Dualband Bandpass Filter Based on Via-Coupling and Stub-Loaded Resonator

为了适应未来无线通信多制式集成的发展需求,提出一种滤波性能优良、中心频率和带宽均独立可控的双通带带通滤波器。孔耦合通过两个谐振器之间的金属化通孔结构形成谐振器之间的磁耦合机制。枝节加载谐振器是在传统二分之一波长微带谐振器的中间加载短路或开路枝节,以形成两个谐振频率独立可控的双模谐振器。结合这两种技术,设计了一种性能优良的、两个通带中心频率和带宽均独立可控的双通带带通滤波器,并通过仿真和实验测试双重手段对其进行了验证,仿真和测试结果吻合良好。结果表明:所设计的双通滤波器两个通带中心频率分别为3.9和6.2 GHz;相对带宽分别为6.4%和5.6%;带内插入损耗分别为1.0和1.6 dB;带内回波损耗分别为20和14 dB。双通带滤波性能良好。所提出的双通带滤波器可适用于未来多制式集成无线通信系统。

In order to adapt to the multi-system integration trend of the future wireless communications,a kind of dualband bandpass filter with excellent filtering performance and independent tunability of center frequencies and bandwidths is proposed.The via-coupling is a kind of magnetic coupling mechanism,which is constructed by the structure of the metallic via between two resonators.The stub-loaded resonator is a kind of dual-mode resonator realized by attaching a shortended or open-ended stub at the center of a traditional microstrip half-wavelength resonator.Its two resonating modes can be independently adjusted.Combined with of the above techniques,a dualband bandpass filter is designed with excellent filtering performance as well as independent control of the center frequency and bandwidth of the two passbands.The proposed dualband bandpass filter is verified by both simulation and experiment.Good agreement between the simulation and experiment results can be observed with center frequencies of 3.9 and 6.2 GHz,fractional bandwidths of 6.4%and 5.6%,in-band insertion losses of 1.0 and 1.6 dB.Therefore,the proposed dualband bandpass filter is a good candidate for future multi-system integrated wireless communication systems.