SIR带状线带阻滤波器的设计

将具有阻带特性的微带马刺线结构引入到带状线中,设计了一款中心频率为2.32 GHz,相对带宽为9.5%,阻带衰减为50 dB的三阶马刺线式带阻滤波器。相比于传统的并联开路短截线型带阻滤波器,马刺线式带阻滤波器的横向尺寸大为减小,结构更加紧凑。采用SIR(stepped-impedance resonator)结构,按相同指标设计了一款三阶SIR马刺线式带阻滤波器。与马刺线式带阻滤波器相比,SIR马刺线式带阻滤波器结构更为紧凑,纵向尺寸缩小约17%,并具有更好的谐波抑制特性。     

Compact tri‐wideband bandpass filter with multiple transmission zeros

This paper presents a tri‐wideband bandpass filter (TWB‐BPF) with compact size, high band‐to‐band isolation, and multiple transmission zeros (TZs). The proposed TWB‐BPF is based on a multiple‐mode resonator (MMR), which is interpreted by the method of the even‐ and odd‐mode analysis technique. The MMR can excite 11 resonant modes, where the first two modes comprise the first passband, the next four modes form the second passband, and the last five modes are used to generate the third passband. In addition, 10 TZs are yielded to obtain high band‐to‐band isolation and wide stopband suppression characteristics up to 14.95f_c1 (f_c1 is the center frequency of the first passband). To verify the proposed filter, a TWB‐BPF with 3‐dB fractional bandwidths (FBWs) of 37.4%, 43.5%, and 40.4% is designed, fabricated, and measured.     

Compact microstrip stepped impedance wideband bandpass filter

A novel wideband bandpass filter with a very compact size is presented in this article. Using a side-coupled stepped impedance resonator, wideband characteristics with adjustable centre frequency and 3-dB fractional bandwidth can be obtained easily. Finally, a filter sample is designed and fabricated to provide an experimental verification on the proposed topology. Good insertion/return losses, flat group delay, wide bandwidth as well as ultra compact size are achieved as demonstrated in both simulation and experiment, which makes this filter a very promising candidate for applications in future wideband communication system.     

基于环形谐振器的平衡式带通滤波器

提出了一种基于多模环形谐振器实现的平衡式带通滤波器, 其主要由加载了电阻和短路枝节的环形谐振器和两对平衡端口构成.所提出的滤波器能够以单个谐振器获得差模的双模响应, 并且具有结构简单, 共模抑制高, 带宽可进行有限控制(4% ~ 9%)的优点.为验证理论预期的可实现性, 在RO4003C基板上设计了一个工作在1.87 GHz的平衡式带通滤波器.实验结果表明该滤波器的20-dB阻抗匹配带宽为8.9%, 中心频率处的插入损耗为0.86 dB, 在1 ~ 3 GHz频率范围内的共模抑制大于30 dB.     

Compact and high-performance bandpass filter and diplexer based on SCMRC-loaded SIR

Bandpass filter (BPF) and diplexer, which are required to be compact size and high performance, are widely used in modern wireless communication systems. In this article, novel BPF and diplexer are designed using the proposed resonator called spiral compact microstrip resonator cell (SCMRC)-loaded stepped-impedance resonator (SIR). The SCMRC-loaded SIR is proposed using the slow-wave structure SCMRC to replace the low-impedance section of the conventional SIR. Compared with the conventional SIR, the new SCMRC-loaded SIR has a compacter size and can generate a transmission zero above its fundamental resonant frequency. As examples, a BPF with the central frequency at f ₀?=?1?GHz and a diplexer operating at 0.9/1.57?GHz are designed and fabricated. The fabricated BPF occupies a compact size of 0.07 λ ₀?×?0.035 λ ₀ and has a??60?dB rejection level wide stopband from 1.2 f ₀ to 3.8 f ₀. The fabricated diplexer occupies a compact size of 0.076 λ ₀?×?0.128 λ ₀ and has an up to??50?dB output isolation. Good agreement can be observed between the simulations and the measurements.     

Compact wideband bandpass filter using quad mode resonator

This paper presents a compact wideband bandpass filter for TETRA band applications. The proposed filter design is based on a quad mode resonator designed using small rectangular loop loaded with four Stepped Impedance Stubs (SISs) and a short circuit stub. The four modes of the resonator help in generating a wide passband. The use of SISs makes the filter compact. In addition to four transmission poles, the resonator inherently generates a transmission zero above the higher end of passband. Two transmission zeros are generated by the input/output coupling which helps in increasing the selectivity and also for achieving wide stopband. This filter provides a 3 dB fractional bandwidth of 30.33% and maximum insertion loss of 1.3 dB at the center frequency 0.36 GHz with a compact size of 0.125 λ_g × 0.085 λg (4.1 × 2.78 cm²).     

Multi-mode multi-band bandpass filter using hexagonal patch resonator

Resonant performances of the hexagonal resonators are analysed, and new tri-mode tri-band bandpass filter which operates at 2.5/2.8, 5.2/5.5 and 7.9/8.5 GHz with insertion loss of no more than 1.3 dB is presented by using a single fractal hexagonal resonator. It shows with fractal-shaped defection in hexagonal patch, filter performance is greatly improved and dual and tri-band bandpass filters can be implemented. The tri-band designs are demonstrated by experiment. The new hexagonal filter has outstanding advantages of multiple-band operation, miniature size, simple and compact structure without resonator coupling gaps. All these features are quite useful for applications in RF circuits.     

基于折叠枝节加载多模谐振器的超宽带滤波器

针对超宽带滤波器的插入损耗和选择性问题,提出一种基于折叠枝节加载多模谐振器结构的超宽带滤波器。通过调节谐振器的阻抗比及电长度比,可以控制谐振频率。仿真与实验结果吻合良好,表明采用折叠枝节加载形式,可以使滤波器具有低插入损耗和良好的选择性。通带范围在2.9~10.7 GHz,带内插入损耗优于1 d B,实现相对带宽114%。     

Dual-band bandpass filter based on mixed electric and magnetic coupling of the hybrid quasi-lumped resonator

A novel compact dual-band bandpass filter based on mixed coupling of the hybrid quasi-lumped resonator is proposed. The filter is composed of two independent signal paths, each can generate one passband with two identical hybrid quasi-lumped resonators. The proposal combines the mixed electric and magnetic coupling technology with this novel resonator in the filter design. Analysis of the filter has been done with the equivalent circuit method. To validate the approach, a dual-band bandpass filter operating at 2.4/5.2 GHz has been fabricated. Both passbands were realised with mixed coupling. An additional transmission zero is generated at either passband. Final fabricated filter has good band skirt, low insertion loss and good out-of-band performance. Reasonable agreement is found between the calculated, simulated and measured results. The implementation area is 0.21λ_g × 0.12λ_g.     

Ultra wideband filter using dumbbell-etched stepped impedance resonator

In this article, an ultra wideband bandpass filter using the dumbbell-etched stepped impedance resonator (SIR) is presented. The filter consists of a dumbbell-etched SIR with an impedance ratio K?>?1 and the enhanced coupled input/output lines. The SIR is folded into a dumbbell shape to achieve a smaller circuit size than the filter with conventional SIR. The bandwidth can be analysed using the image-parameter method to obtain the proper dimension of the coupled lines and verified using electromagnetic simulation. The measured 3?dB fractional bandwidth of 110% and insertion loss |S ₂₁| less than 3?dB over the entire passband are achieved.     

基于非对称共地λ/4谐振器对的三频带滤波器设计

提出了一种全新的谐振器结构——非对称共地λ/4谐振器对.此谐振器对由一个4 UIR谐振器和λ/4 SIR谐振器通过共用一个接地通孔组合而成.其中SIR谐振器工作于2.4 GHz与5.2 GHz频段,UIR谐振器工作于3.6 GHz频段,据此设计制作了一个四级三频带切比雪夫型滤波器并进行了测试和仿真.结果表明,该滤波器的测试结果与仿真符合良好.利用此谐振器对设计的滤波器不仅体积大大减小,而且每个通带的位置及其耦合特性都能够独立调谐.     

基于非对称共地λ/4谐振器对的三频带滤波器设计

提出了一种全新的谐振器结构——非对称共地λ/4谐振器对。此谐振器对由一个λ/4 UIR谐振器和λ/4 SIR谐振器通过共用一个接地通孔组合而成。其中SIR谐振器工作于2.4 GHz与5.2 GHz频段,UIR谐振器工作于3.6 GHz频段,据此设计制作了一个四级三频带切比雪夫型滤波器并进行了测试和仿真。结果表明,该滤波器的测试结果与仿真符合良好。利用此谐振器对设计的滤波器不仅体积大大减小,而且每个通带的位置及其耦合特性都能够独立调谐。     

低损耗双谐振微带带通滤波器设计

为了既满足实现双谐振的零度馈电结构,又能实现阻抗匹配,采用双点双线馈电技术和具有开口环、阶跃阻抗谐振双重特性的结构设计双通带滤波器。版图仿真结果表明:两个谐振频率分别为2.7 GHz和5.05 GHz,符合射频电子标签所需的两路信号,其对应的回波损耗分别为-38 dB和-49 dB,插入损耗为-0.2 dB和-0.4 dB,从而实现了低损耗特性和尖锐的选择性。     

Miniaturized microstrip bandpass filter designed using rectangular dual spiral resonator

A miniaturized microstrip bandpass filter based on a rectangular dual spiral resonator (DSR) is proposed in this paper. The rectangular DSR bandpass filter is centered at 3.65 GHz to suit for Wireless LAN (IEEE802.11y) application. The proposed filter offers transmission zero at the high side of out-of-band response. Across the bandwidth, the measured minimum insertion loss is about 1.7 dB, while the measured return loss is better than 19 dB. Measurement results are good agreement and closed to the simulated ones. The total circuit size of the miniaturized bandpass filter is about 0.145λ_g by 0.135λ_g, where λ_g is the guided wavelength at 3.65 GHz.     

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。     

Compact differential bandpass filter with a narrow notched band using APCL structure suitable for UWB application

A compact differential band pass filter with asymmetric parallel-coupled lines (APCL) and center frequency of 5.6 GHz is proposed in this paper. The APCL suppresses unwanted RFID signals by introducing a fully tunable notched band at 6.8 GHz. By combining the concept of transmission matrix with modal analysis and extracting a novel model for symmetric three parallel coupled lines (SPCL), role of each resonant frequency is clearly explained. Measurement results in the differential mode show a pass band from 3.1 to 8.1 GHz and a wide stop band from 9.1 to 16 GHz with attenuation of more than 20 dB. In addition, S₂₁ in common mode is lower than −10.5 dB over the pass band.     

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.     

Novel design of tri-band bandpass filter based on fractal-shaped geometry of a complementary single split ring resonator

A novel electrically small composite right/left-handed transmission line (CRLH TL) cell based on the Minkowski-shaped geometry of a complementary single split ring resonator is proposed and analysed by the S parameters extraction method. EM simulation results have confirmed the roughly tri-band response of the proposed CRLH TL cell attributed to the fractal multiband nature. A tri-band bandpass filter (BPF) centred at 1.1, 2 and 2.74?GHz with minimum insertion loss 0.4, 1.1 and 1.45?dB was synthesised and fabricated by employing an additional two Hilbert-shaped quarter-wave open-circuit stubs which provided transmission zeros located between passbands to obtain high selectivity. This simple design concept was verified by measurement as well as simulation results.     

基于E型谐振器的三陷波超宽带带通滤波器

针对超宽带系统中存在窄带信号干扰的问题,提出了一种加载E型谐振器的多模谐振器(Multimode Resonator,MMR)结构,采用内嵌开路枝节的方法设计了一款三陷波超宽带滤波器,并且通过调节内嵌开路枝节的长短,实现了双陷波的性能。该超宽带带通滤波器通带频带范围为3. 1~10. 2 GHz,通带内插入损耗小于1 d B,相对带宽为107%。其中,实现的三陷波滤波器的三个陷波中心频率分别为3. 8,5. 1和6. 6 GHz。通过调节内嵌开路枝节的长短,可以实现双陷波到三陷波之间的转换,仿真结果与理论分析一致。     

多次谐波抑制的微波滤波器

提出一种新型的具有多次谐波抑制功能的发夹型微波带通滤波器,主要工作在2GHz频率。对该滤波器通过仿真优化,并进行实际设计测量。在该结构滤波器中,采用阶跃阻抗结构的发夹谐振器来达到缩小尺寸、多次谐波的目的。该滤波器相比于传统的微带线发夹型滤波器具有尺寸小,频率选择性好,阻带宽的特点。