【作者】 罗伟；

【导师】 陈晨；

【作者基本信息】 重庆大学 ， 信息与通信工程， 2024， 硕士

【摘要】 随着无线通信技术的发展,通信系统向着低成本、高性能、小型化、集成化的方向发展,其中滤波器件在系统中因其具有分离信号、抑制干扰等关键作用而备受关注。基片集成波导（Substrate Integrated Waveguid:SIW）结构作为一种新型的技术,因其高性能、低损耗、易集成等特点被广泛应用于滤波器的设计中。本文基于SIW多模谐振腔,对具有宽阻带特性SIW滤波器、多通带SIW滤波器以及高选择性的SIW滤波器进行了研究,主要研究内容如下:（1）基于微扰型SIW双模谐振腔的宽阻带滤波器。首先对SIW谐振腔内的谐振模式进行分析,通过引入金属化通孔调节TE₁₀₁模式并与TE₂₀₁模式构成双模频率,同时改变TE₃₀₁和TE₁₀₃模式的电场分布使其能被抑制。其次结合模式耦合控制技术使杂散模式不被激励或者接收,实现阻带宽度的扩展。然后基于单个SIW双模谐振腔提出了一款中心频率为10GHz的二阶宽阻带滤波器,可以同时抑制TE₂₀₁和TE₂₀₃模式之间的七个杂散模式,滤波器的20d B抑制度阻带宽度可以扩宽到2f₀。最后通过级联两个SIW双模谐振腔拓展到了四阶宽阻带滤波器,滤波器的抑制度上升至30d B阻带宽度仍然保持2f₀,50d B抑制度阻带宽度达到1.4f₀。（2）基于微扰型SIW四模谐振腔的多通带滤波器。首先对微扰型SIW谐振腔的前四个模式特性进行分析,并控制TE₁₀₁与TE₂₀₁模式、TE₁₀₂与TE₂₀₂模式构成两对双模频率。其次基于此结构提出一款通带中心频率可控的SIW双通带滤波器。在不增加电路尺寸的同时,通过在谐振腔表面蚀刻一对互补开口谐振环（Complementary Split Ring Resonator:CSRR）实现一款SIW三通带滤波器。最后,为了进一步扩展通带数量,在相同的平面电路尺寸下,采用多层结构耦合控制技术,实现SIW四通带滤波器。（3）基于SIW双模谐振腔的高选择性滤波器。首先分析在SIW谐振腔中双模频率对应的模式数与宽长比W/L的关系。其次分析了以TE₁₀₂和TE₃₀₁模式为例的七种双模谐振腔及其对应的频率响应曲线,并验证了基于双模谐振腔能在通带外形成一个传输零点来改善选择性能。然后同样以TE₁₀₂和TE₃₀₁模式为例,为了改善通带选择性,基于该双模谐振腔并引入CSRR结构提出了一款中心频率在10.16GHz且相对带宽为11.8%的高选择性三阶SIW滤波器。最后采用不对称的结构实现了中心频率在10.1GHz且相对带宽为4.9%的四阶准椭圆型SIW滤波器。这两种设计方法均可应用到其余六种SIW双模谐振腔,以此实现高选择性滤波器。更多还原

【Abstract】 With the development of wireless communication system,the equipments are developing in the directions of low-cost,high-performance,miniaturization and integration,in which the filters are attracting attention as the frequency selector in the system because of their key roles of separating signals,suppressing interference and so on.The substrate integrated waveguide（SIW）structure,as a novel type of technology with high-performance,low loss,easy to integrate and other characteristics are widely used in the design of filters.Based on the SIW multimode resonant cavity,the SIW multi-band,wide-stopband and high-selectivity bandpass filters are researched in this thesis.The main contents are as follows:（1）SIW wide-stopband filters based on dual-mode cavity.Firstly,the characteristics of resonant modes in the SIW cavity are analyzed,and through changing the electric field distribution of the fundamental mode and constituting a pair of dual-mode frequencies with TE₂₀₁ mode,and simultaneously controlling the electric field distributions of TE₃₀₁and TE₁₀₃ modes to be suppressed.Secondly,by combining the mode suppression technique so that the high-order modes can not to be excited or received,and the width of stopband can be extended.Then a second-order wide-stopband filter centered at10GHz using a single SIW dual-mode cavity is proposed,which can suppress seven higher modes between TE₂₀₁ and TE₂₀₃ modes at the same time,and the stopband can be extended to 2f₀ with the suppression level below 20d B.Finally,a fourth-order wide-stopband filter is realized by cascading two SIW dual-mode cavities,and the suppression level increases to 30d B,while the width of stopband remains 2f₀,and the stopband can reach 1.4f₀ with suppression level below 50d B.（2）SIW multi-band filters based on quad-mode cavity.Firstly,the characteristics of first four resonant modes in the perturbed SIW cavity are analyzed.TE₁₀₁ and TE₂₀₁modes,TE₁₀₂ and TE₂₀₂ modes can constitute two pairs of dual-mode frequencies.Secondly,a SIW dual-band filter with controllable center frequencies of two passbands is proposed based on the quad-mode cavity.Then,a SIW tri-band filter is proposed and realized by etching a pair of complementary split ring resonators（CSRR）on the top of the SIW cavity without increasing the circuit size.Finally,to further increase the number of passbands with the same planar circuit size,one SIW quad-band filter is proposed and realized by adopting a multi-layer structural coupling control technique.（3）SIW high-selectivity filters based on dual-mode cavity.Firstly,the width-to-length ratio W/L of the SIW cavity is analyzed to realize the dual-mode frequencies.Secondly,seven dual-mode resonant cavities and the corresponding frequency responses are analyzed with the TE₁₀₂ and TE₃₀₁ modes as examples,and it is verified that the selectivity is improved based on that the dual-mode resonant cavities can generate a transmission zero outside the passband.Then,to further improve the passband selectivity,also using TE₁₀₂ and TE₃₀₁ modes as examples.A third-order SIW bandpass filter centered at 10.16 GHz with a fractional bandwidth of 11.8%is proposed based on the dual-mode cavity and a CSRR structure.Finally,a fourth-order quasi-elliptic SIW filter centered at 10.1 GHz with a fractional bandwidth of 4.9%is realized based on an asymmetric structure.Both design methods can be applied to the remaining six SIW dual-mode cavities as a way to realize high-selectivity filters.更多还原