毫米波双通带基片集成波导滤波器设计

提出了一种新型毫米波双通带基片集成波导(SIW)滤波器,该滤波器由双模基片集成波导和双模带线谐振器构成。其中双模带线谐振器嵌入到双模基片集成波导谐振腔中,不占据额外的电路面积,利用双模带线谐振器的TEM模和双模基片集成波导谐振腔的两个简并模式TE102、TE201,可分别形成两个相互独立的通带,因此该滤波器的设计具有很大的灵活性。所设计的双通带滤波器具有三个传输零点,实现了良好的带外抑制和带间隔离度。该双通带滤波器工作于28.4GHz和32.2GHz,3dB带宽分别为2%和3%。最终的测试结果和仿真结果相吻合,证明了该设计方法的可靠性。     

基于双模开环谐振器的双频带滤波器设计

基于开环双模谐振器设计了一种双频带通滤波器,由两个中心重合的正方形开口环谐振器组成。分析该谐振器的奇偶模谐振频率与传输零点,每个通带内有两个谐振模式。该滤波器中心频率分别为4.5 GHz和6.5 GHz,3 dB相对带宽FBW分别为11%、5%,两通带带内插入损耗分别小于0.6 dB、1.4 dB,带内回波损耗分别优于19.5 dB、16.5 dB,高频处阻带抑制达到50 dB,两通带之间隔离度达到53 dB,尺寸仅为6 mm×11 mm×1.09 mm。     

横向双模双频滤波器设计

基于横向滤波器耦合结构,采用支节加载双模谐振器,设计了中心频率位于1.57 GHz(GPS应用)与2.4GHz(WLAN应用)的双频微带滤波器。由短路支节加载双模谐振器形成第一个通带,开路支节加载双模谐振器形成第二个通带,两个谐振器被输入/输出馈线隔离,每个通带的中心频率与带宽可以单独调节。测试结果表明:两个通带内的最小插损分别为2.18,1.35 dB,3 dB带宽分别为5.2%,6.8%,回波损耗均小于16 dB,三个传输零点分别位于1.28,2.08,2.71 GHz处。该滤波器具有尺寸小、带外选择性好等优点。     

圆形开槽贴片微带双模带通滤波器

提出了一种新颖、简单的圆形贴片上刻蚀小方槽的微带双模带通滤波器结构.该滤波器仿真的通带中心频率为5.9 GHz,最大回波损耗优于-31.5 dB,通带内最小插入损耗为- 0.7 dB,3 dB带宽为23.73％.实测和仿真结果相一致.     

基于T 型谐振器的新型可重构滤波器的设计

基于T 型谐振器结构,设计了一款新型小型化可重构滤波器。它可以通过开/ 关射频开关,实现三种滤波器的重新配置。这三种模式分别为带阻滤波器(BSF)、宽阻带带阻滤波器(WB鄄BSF)和双模带通滤波器(DB-BPF)。设计并制造了一款小型可重构滤波器实物(εr =2.65,h =1 mm)。其中,带阻滤波器的阻带中心频率为3.89 GHz,-3 dB相对带宽为90.9% (2.12 - 5.65 GHz);宽带带阻滤波器的阻带中心频率为3.54 GHz,-3 dB 相对带宽为137.85%(1.1～5.98 GHz);双模带通滤波器的两个通带中心频率分别为1.53 GHz 和6.89 GHz,-3 dB 相对带宽分别为17. 6%(1.4～1.67 GHz)和1.16% (6.85～6.93 GHz),两通带之间回波损耗优于15 dB。实物测试结果与仿真结果基本一致。     

基于奇偶模分析法的四模谐振器结构的双通带带通滤波器设计

提出了一款基于四模谐振器的新型双通带带通滤波器.设计的四模谐振器基于微带线结构,由四个开路枝节和一个短路枝节组成.两次采用奇偶模分析法对该四模谐振器结构进行分析.该四模谐振器的每个模式能够实现独立调节,同时每两个模式形成一个通带.采用源与负载耦合的馈电方式,提高滤波器的带外抑制性.该滤波器具有四个传输零点和四个传输极点.测试结果表明,该双模双通带滤波器工作于2.08GHz和6.07GHz,3dB带宽分别为11.06%和7.74%.设计的滤波器具有紧凑的结构,只有0.28λ_g×0.11λ_g大小.     

基于折叠型SIR 谐振器的双通带滤波器设计

文中提出了一种基于折叠型SIR 谐振器的双通带频率可控的微带滤波器,它由SIR 谐振器特性结合 传输线理论实现。该滤波器设计为具有两个自由度,调节谐振器的导带宽度可以对两个通带之间的频率及其间隔 进行调节。文中还研究了调整谐振器导带长度对滤波器频率特性的影响。测试结果表明,该微带滤波器有两个通 带,其中心频率分别为2. 79 GHz 和3. 90 GHz,带内最小插入损耗分别为-0. 96 dB 和-3. 0 dB,带内最小回波损耗分 别为-42 dB 和-18 dB,相对带宽分别为5. 7%和6. 7%。仿真和测试结果的一致性证实了滤波器设计的有效性。     

基于折叠双模谐振器结构的微带带通滤波器

设计了一种采用折叠双模谐振器结构的新型双模微带带通滤波器。通过在折叠双模谐振器两侧加载交叉耦合结构,使通带两端产生一对传输零点。实验结果表明,该滤波器具有结构紧凑,体积小,损耗低,带外抑制性能好等优点,且其中心频率为3.65 GHz,通带为2.5～4.8 GHz,最大回波损耗优于-33.5 dB,最小插入损耗为-0.18 dB,实测结果和仿真结果相吻合。     

基于折叠双模谐振器结构的微带带通滤波器

设计了一种采用折叠双模谐振器结构的新型双模微带带通滤波器。通过在折叠双模谐振器两侧加载交叉耦合结构,使通带两端产生一对传输零点。实验结果表明,该滤波器具有结构紧凑,体积小,损耗低,带外抑制性能好等优点,且其中心频率为3.65GHz,通带为2.5~4.8GHz,最大回波损耗优于-33.5dB,最小插入损耗为-0.18dB,实测结果和仿真结果相吻合。     

一种新型双环双模带通滤波器

本文提出了一种由一个环形谐振器和一个微扰小环构成的新型双环双模带通滤波器。微扰小环具有两个可调参数,增加了调整双模的自由度,从而更容易地调节双模,便于实现滤波器的小型化。抽头输入输出耦合结构可以方便地调整双模滤波器的两个传输零点,从而改善滤波器的通带特性。最后实现了中心频率为2.41GHz,相对带宽为17.77%的双环双模带通滤波器,通带内插入损耗为0.67dB,回波损耗为17dB,且带外衰减大于20dB。     

Balanced Dual-Band BPF With Stub-Loaded SIRs for Common-Mode Suppression

A new fourth-order balanced dual-band band-pass filter (BPF) designed using four coupled bi-section half-wavelength ( $lambda /2$) stepped-impedance resonators (SIRs) is presented. To obtain the required differential-mode (DM) operation with suppressed common-mode (CM) transmission, the SIRs were designed to have the same odd-mode, but different even-mode, resonant frequencies. For that purpose, the two inner SIRs were loaded at the center with T-shaped open stubs of different dimensions so that their even-mode resonant frequencies are shifted away from those of the outer SIRs and that their odd-mode ones remain almost intact. For the fabricated prototype BPF, the measured minimum DM insertion losses for the first and second bands are 2.4 and 2.82 dB, respectively, whereas the measured CM insertion loss is larger than 25 dB in 1–7 GHz.      

Compact Ultra-Wideband Bandpass Filter Using Dual-Line Coupling Structure

This letter presents a novel compact ultra-wideband (UWB) microstrip bandpass filter with spurious response suppression. A dual-mode ring resonator is constituted to allocate its first two resonant frequencies in the UWB band, and the dual-line parallel-coupled structure is used in this compact UWB filter, which is expected to achieve much tighter coupling degree. Simulated and measured results are found in good agreement with each other, showing a wide passband from 4.9 to 10.9 GHz, 15 dB return loss bandwidth of about 5 GHz, minimum insertion loss of 0.49 dB at 7.3 GHz, and wide upper stopband with more than 20 dB attenuation up to 20 GHz.     

Novel Broadband Bandpass Filters Using Y-Shaped Dual-Mode Microstrip Resonators

A Y-shaped dual-mode microstrip bandpass filter (BPF) with input-output cross-coupling is presented. The characteristic of the Y-shaped dual-mode resonator has been investigated. The resonance frequencies of the degenerate modes can be adjusted easily to satisfy the bandwidth of the BPF. A parallel-coupling feed structure with a cross coupling has been used to generate two transmission zeros at the lower and upper stopband, which can improve the out-of-band performance. A broadband dual-mode microstrip BPF has been designed, fabricated, and measured. The simulated and measured results are in agreement generally. Within the 3.1 to 5.4 GHz bandwidth, the measured insertion loss, return loss and group delay variation are below 0.5 dB, above 15 dB, and below 0.2 ns, respectively.      

基于多节SIRs的新型四通带滤波器设计

提出了一种基于多节1/2波长SIRs的具有通带可控的紧凑型四通带滤波器。该滤波器由上下两个谐振器A和B组成,谐振器A由两节1/2波长SIRs中心加载一段短路枝节组成,控制第二和第三通带;谐振器B由三节1/2波长SIRs中心加载一段短路枝节组成,控制第一和第四通带,最终得到了尺寸为8.09 mm×14.12 mm(0.10λ_g×0.17λ_g)的四频带通滤波器。实验结果表明,该滤波器的通带可控并且满足低损耗的要求,4个通带的中心频率分别为2.22/3.66/5.63/7.52 GHz,插入损耗分别为0.32/0.41/1.38/0.43 dB,每个通带的回波损耗都优于20 dB,实验结果与理论分析一致。     

新型的平面双模椭圆函数带通滤波器

根据传统的方形贴片双模滤波器,提出了一种新颖的带有两个切角的平面双模带通滤波器结构.该结构使用单个贴片谐振器并且没有耦合缝隙,通带两端各有一个衰减极点,有效减小了滤波器的辐射损耗.对该滤波器结构进行改进,又提出了一种带有两个相互正交、长度不等槽线的双模椭圆函数带通滤波器结构.该滤波器在中心频率1.8GHz处,回波损耗达到31.53 dB,通带内最小插损达到0.01 dB,3 dB相对带宽为19.44%.采用Ansotf公司的En-sem ble 8.0仿真软件进行的仿真研究.仿真结果表明该结构可以更加有效地减小辐射损耗,增加带宽,且体积比传统滤波器减小了约40%,有利于小型化.     

Dual-Band Bandpass Filters Using Stub-Loaded Resonators

Dual-band bandpass filters using novel stub-loaded resonators (SLRs) are presented in this letter. Characterized by both theoretical analysis and full-wave simulation, the proposed SLR is found to have the advantage that the even-mode resonant frequencies can be flexibly controlled whereas the odd-mode resonant frequencies are fixed. Based on the proposed SLR, a dual-band filter is implemented with three transmission zeros. To further improve the selectivity, a filter with four transmission zeros on either side of both passbands is designed by introducing spur-line. The measured results validate the proposed design.     

Multilayer Dual-Mode Dual-Bandpass Filter

A dual-mode dual-bandpass filter for the U-NII bands is proposed and demonstrated. Its effective size reduction is achieved by using a multilayer configuration. The first and the third layers incorporate microstrip dual-mode bandpass filters with operating center-frequencies of f₁ =5.2 GHz and f₂ =5.8 GHz, respectively. The second layer is used as a common ground plane for both filters, which also serves as a decoupling interface. Capacitive coupling transition is used to connect both filters to I/O coplanar waveguide (CPW) ports. Single and dual-band passband filter prototypes are designed, fabricated, and measured in this work, thus validating the design principle. Designed topologies of single passband filters with center frequencies of 5.2 and 5.8 GHz exhibit an out-of-band rejection better than 40 dB with a 3 dB bandwidth of 5.8% and 6%, respectively. The proposed multilayer dual-passband response with center frequencies of 5.2 and 5.8 GHz provide band-to-band isolation better than 30 dB. Measured insertion losses are lower than 2.76 dB, with 3 dB bandwidth lower than 5%.     

低损耗双模微带贴片带通滤波器研究

首先提出了一种新颖、简单的带有两个切角的双模微带带通滤波器结构。该结构使用单个贴片谐振器并且没有耦合缝隙,通带两端各有一个衰减极点,可以有效减小滤波器的辐射损耗。对该滤波器结构进一步改进,又提出了一种中心频率1.8GHz相互正交槽线的新型双模微带带通滤波器结构。该滤波器在中心频率1.8GHz处,回波损耗达到31.65dB,通带内最小插损为0.01dB,3dB带宽为19.44%。研究结果表明该结构可以进一步减小辐射损耗,并且可以减小滤波器的体积,有利于小型化。     

Quad Band Substrate Integrated Waveguide Cavity Backed Slot Antenna Using Balanced Shorting Vias

In this paper, low profile cavity-backed cross shaped slot antenna using substrate integrated waveguide (SIW) technology is proposed for obtaining quad-band response. In order to generate four distinct frequencies, a crossed slot is etched on the back of the dielectric substrate and three balanced shorting vias (metallic vias) are included across the longitudinal slot. Furthermore, the electric field distribution has been utilized for understanding the working principle of the proposed design. Balanced shorting vias modify the current distributions of the cavity, which consequently produces two resonant frequencies in X-band and two more resonant frequencies in Ku-band. Finally, the proposed quad-band antenna is fabricated using printed circuit board (PCB) technology and the results are experimentally verified. With the height of 0.026λ₀, the measured results show that the proposed design resonates at 8.6 , 10.2 , 13.2 , and 14.8 GHz and exhibits a –10 dB impedance bandwidth more than 150 MHz at corresponding frequencies. The proposed antenna attains a peak gain of more than 6 dBi at the corresponding resonant frequencies, respectively. Those amicable characteristics, e.g., low profile, uni-directional radiation pattern, ease of fabrication, quad-band response and moderate gain, make the proposed antenna suitable for both radar and satellite systems.