Compact wide stopband lowpass filter using spiral loaded tapered compact microstrip resonator cell

A new spiral loaded tapered compact microstrip resonator cell (SPLT-CMRC) is presented. The addition of spiral stubs to the CMRC creates transmission zeroes in the stopband which extended the stopband of the ?lter. The proposed resonator is used to design a compact lowpass ?lter (LPF) with wide and high rejection in stopband. The fabricated ?lter has a 3 dB cutoff frequency at 8 GHz. The insertion loss in the passband is less than 0.2 dB from DC to 7.2 GHz. The proposed ?lter has wide stopband from 9.47 to 40 GHz with attenuation level of ?20 dB. The demonstrated filter is designed and fabricated. There is a good agreement between the measured and simulated S-parameters.     

Compact microstrip lowpass filter with very sharp roll-off using meandered line resonators

In this paper, a new compact size microstrip lowpass filter (LPF) with a very sharp roll-off is presented to apply in the modern wireless networks. The proposed LPF is designed using the series main resonators with meandered lines based on inductor-capacitor (LC) equivalent circuit analysis. The main goal is to achieve maximum-sharp roll-off by maintaining a wide stopband bandwidth and high return loss (RL). The main resonator of the proposed filter is consisted of two meandered line hairpin resonators (MLHR), and a meandered line T-shaped resonator (MLTR). The designed suppressor is composed of two coupled radial stubs to create a wide stopband. Low return loss in the passband, which has been created by the main resonator, is resolved by the suppressor structure with high return loss. The measured results show a ??3 dB cut-off frequency of 1.93 GHz. The very sharp transition band starts at 1.93 to 1.97 GHz (from ??3 to ??20 dB). The stopband is from 1.97 to 19.9 GHz (with the suppression level of ??20 dB). Also, the total size of the proposed LPF is only 13.3?×?10.1 mm².

     

Compact microstrip lowpass filter using meandered unequal T-shaped resonator with ultra-wide rejection band

In this paper, a compact lowpass filter (LPF) with ultra-wide rejection band has been presented. In fact, a novel meandered semi-hairpin resonator has been used and the stopband characteristics have been improved by using a combinatorial suppressing unit. The suppressing unit contains a combination between T-shaped and semi-circular patches, which are loaded symmetrically to the designed resonator. For the proposed LPF, the-3 dB cut-off frequency has been adjusted to 2.2 GHz. After simulations, the proposed LPF has been fabricated and tested. The experimental results validated that the rejection bandwidth is expanded from 2.471 GHz to 28.62 GHz with corresponding attenuation level of −20 dB. The transition band is only 0.271 GHz from 2.2 GHz to 2.471 GHz with corresponding attenuation levels of −3 dB to −20 dB, respectively. In addition, the measured maximum insertion loss and return loss in the passband, from DC to 2.04 GHz (93% of the passband region) are 0.2 dB and 17 dB, respectively.     

A novel microstrip lowpass filter with sharp roll-off and ultra-wide stopband using SICMRC

This paper presents a novel microstrip lowpass filter with sharp roll-off and ultra-wide stopband using stepped-impedance resonator and bended transmission line structure. The filter includes stepped-impedance prototype filter and stepped-impedance compact microstrip resonator cells that are combined in one structure. The proposed filter has good specifications such as sharp roll-off, ultra-wide stopband and low insertion loss. The transition band is approximately 0.25 GHz from 1.75 to 2 GHz with corresponding attenuation levels of ?3 and ?40 dB. The attenuation level in the stopband is better than ?20 dB that is achieved from 1.94 to 23 GHz, and the insertion loss in the passband is less than 0.4 dB. The proposed filter is fabricated and measured, and the simulation and measurement results are found to be in good agreement with each other.     

一种基于LTCC 的吸收式低通滤波器的设计

为了阻止阻带反射信号回到信号源,设计了一款LTCC半分布式吸收低通滤波器。该滤波器通过衰减电阻把阻带能量衰减掉,在不增加插入损耗的情况下达到吸收阻带反射信号的效果。仿真结果表明,该款滤波器的3 dB截止频fc=2.5 GHz,带内回波损耗大于20 dB,6fc处对反射信号的吸收大于12 dB,3.7 GHz处的带外抑制大于20 dB,模型尺寸仅为4.8 mm×3.6 mm×1.43 mm。     

A wideband stepped-impedance rectangular-ring resonator bandpass filter with multiple notched bands

A configuration of wideband bandpass filter (BPF) with multiple notched bands is presented. Proposed BPF is based on stepped-impedance resonator. By utilising dual stepped-impedance resonators in folded topology a rectangular-ring resonator is formed. Two notched bands in the passband are achieved without using asymmetrical coupled lines. In other words, the filter configuration is capable of producing notched bands. It should be noted that additional information on filter performance and design is presented. Measurement results are presented to approve propounded filter characteristics. The measured passband of the second proposed filter is from 3.68 to 10.2 GHz with insertion loss of –1.76 dB in the first passband at the centre frequency of 4.45 GHz. The measured notched band frequencies are about 5.45 and 7.95 GHz with rejection of –21.77 and –20.82 dB, respectively. The return loss in the passband is better than –11.4 dB.     

一种IPD吸收式低通滤波器的设计

为解决反射信号损害系统性能的问题,提出了一种具有高带外抑制和高带外吸收的小型化吸收式低通滤波器。该滤波器通过高通通路和低通通路实现了吸收式低通滤波器;通过抑制增益支路实现了高带外抑制。利用ADS和HFSS仿真软件对滤波器结构进行优化设计,并进行了实物的加工和测试。实测结果表明:该滤波器的3 dB截止频率为4 GHz,其带内最小插入损耗0.88 dB,通带内DC到3.5 GHz的回波损耗大于20 dB,阻带回波损耗大于10 dB,10.5 GHz处的阻带抑制大于45dB,从8 GHz到30 GHz的带外抑制大于33 dB,实测结果与仿真结果有较好的吻合。该滤波器尺寸仅为1220μm×650μm×87.71μm,相比传统PCB、LTCC工艺的滤波器,体积大大缩小,符合现代射频与微波系统小型化的发展趋势。     

多口三环CSRR微带低通滤波器的研究与设计

提出一种新型的多口三环CSRR结构,利用CSRR谐振器的单极点低通特性和环与微带线之间的耦合,构成低通滤波器.分析该结构的等效电路模式,指出谐振频率的计算公式.使用HFSS适当优化参数,可以得到性能良好的低通滤波器.其-3 dB截止频率8.76 GHz,通带内插入损耗小于0.3306 dB,通带内回波损耗小于-13.810 2 dB,衰减15 dB以上阻带带宽达到10.31 GHz.为了改善通带内的回波损耗,在微带线两侧加载并联开路枝节.其-3 dB截止频率8.385 GHz,通带内插入损耗小于0.174 7 dB,通带内回波损耗小于-19.707 7 dB,衰减15 dB以上阻带带宽达到10.7 GHz.     

Novel Bandpass Filter Configuration Using Coupled Linear Tapered Line Resonators

A novel tapped bandpass filter composed of two‐coupled linear tapered‐line resonators (LTLRs) is proposed. Multistepped resonators are applied to analyzing LTLRs, which are difficult to analyze directly. Through this analysis method, fundamental characteristics of LTLRs and their filter design parameters can be easily derived. This new filter has insertion loss less than 0.6dB at 1.9 GHz, the return loss less than 18dB in the range 1.8‐1.93GHz and 12.3% 3dB bandwidth. Experimental results of fabricated filter are in good agreement with the design results.     

小型化宽频带宽阻带微带滤波器的设计

目前研究宽频带微带滤波器的文献很多,但普遍不能同时具有宽频带和宽阻带的性能,且带内回波损耗大,带外抑制差。为此,提出了一种新型的宽频带微带滤波器。该滤波器采用在E型阶跃阻抗谐振器( SIR)中引入U型结构的方法,实现其宽频带宽阻带的性能。对滤波器进行仿真、加工与实测,仿真结果与实测结果吻合良好。加工得到的滤波器3 dB带宽为7.1 GHz,低于-20 dB的高频阻带为9.3 GHz,带内回波损耗低于-23.2 dB,实物尺寸为15 mm伊8.5 mm,具有小型化的特点。实测数据表明,提出的滤波器具有良好的性能,在工程领域具有实际的应用价值。     

A microstrip wideband bandpass filter based on λ/2 stub with spurious passband suppression scheme

In the design of bandpass filters, the use of λ/2 stubs of shunt configuration had been mostly unacceptable due to their effect of narrow stopband bandwidths in the ensuing filters. The design of bandpass filter presented in this article introduces 360° series transmission line segments to increase the stopband bandwidths to an acceptable level without affecting the wide passband. This designed filter has low insertion loss of less than –1.98 dB and a fractional bandwidth of 50% at 6 GHz mid-band frequency. A sharp rejection in the stopband is observed. To further widen the bandwidth of stopbands, a series capacitor and a shunt stub are used. The transmission line model of the filter is in good agreement with measured results. The filter is planar and is fabricated on FR-4 substrate which makes it cost-effective and easy to fabricate.     

基于SIW技术的毫米波滤波器研究与设计

基于基片集成波导（substrate integrated waveguide,SIW）结构设计了两款四阶的耦合带通滤波器,使用三维全波电磁场仿真软件HFSS对设计的两款滤波器进行了仿真设计和优化.由仿真结果分析得出,两款滤波器的工作频率均位于毫米波频段.第一款SIW滤波器实现了切比雪夫型响应,中心频率为20 GHz,带宽为2 GHz,通带内的插入损耗低于1.5 dB,回波损耗低于-20 dB,在阻带中对信号的衰减程度可以达到50 dB.第二款SIW滤波器实现了准椭圆函数型的响应,中心频率为29.1 GHz,带宽为300 MHz,通带内的插入损耗低于1 dB,回波损耗低于-20 dB,在通带到阻带的过渡中实现了两个陷波点.仿真结果表明,在毫米波滤波器设计中引入SIW结构,有利于优化滤波器尺寸,得到较好的滤波器性能指标,是毫米波滤波器发展的一个重要方向.     

Performance improvement and size reduction of microstrip dual-mode bandpass filter

A novel miniaturised dual-mode bandpass filter with multi-arc resonators is proposed. The size of the dual-mode filter can be reduced significantly by using the microstrip dual-mode resonator consisting of multi-arcs; meanwhile insertion loss and spurious response suppression are improved A prototype filter is designed and implemented at 3.6 GHz with 2.8% fractional bandwidth, which shows a low passband insertion loss of 1.02 dB and a wide stopband with rejection better than 20 dB up to about 8.5 GHz.     

一种超宽阻带微带低通滤波器的设计

基于传统阶跃阻抗滤波器,提出了一种易于实现的超宽阻带微带低通滤波器改进设计方案。低阻抗线部分采用扇形微带结构,在同等阶数下,该结构的滤波器与传统阶跃阻抗滤波器相比,具有更紧凑的电路结构以及更好的阻带特性。在滤波器末端并联开路短截线,使得阻带增加额外传输陷波点来抑制寄生通带。利用ADS和HFSS仿真软件对滤波器结构进行优化设计,并进行了实物的加工和测试。实测结果表明,通带3 dB 截止频率为2 GHz,通带内0-1.8 GHz 回波损耗大于20 dB,3-20 GHz 频率范围内的阻带抑制能达到25 dB 以上。     

High Performance Microstrip Low Pass Filter for Wireless Communications

A microstrip low-pass filter using T-shaped resonators is designed to achieve an ultra-sharp transition band and high suppression level. The performance of the resonators is investigated based on an LC equivalent circuit and a transfer function to compute the equations of the transmission zeros. This filter has an acceptable stopband with high insertion loss (28 dB) by adopting a rectangular suppressor. Also, the width of the transition band is 0.09 GHz (with – 3 and ? 40 dB attenuation levels), that exhibits a very high sharpness (ξ = 411 dB/GHz). The proposed filter with a 3 dB cut-off frequency (f_c) of 1.32 GHz presents a high return loss in the passband (17 dB) and high figure of merit of 57,073. The designed filter is fabricated and measured, demonstrating sufficient agreement between the simulation and experimental results.

     

新型的方形贴片双模微带带通滤波器

提出了一种新型的方形贴片双模微带带通滤波器。该滤波器结构有一个切角,并且在贴片中心处开了一个两臂等长的十字槽,采用正交直接馈电方式,并在每条馈线上引入了一节与谐振腔有一定耦合的开路短截线。该结构在上下阻带都产生衰减极点,馈线上引入的微带线有效地抑制了寄生通带,提高了阻带抑制特性。仿真结果表明,该滤波器在中心频率2.9 GHz处,回波损耗优于–30.9 dB,通带内最小插入损耗为–0.1 dB,与实测结果基本一致。     

具有良好选择性及带外抑制的小型低通滤波器

本文提出了一种具有良好选择性以及宽带带外抑制的小型低通滤波器结构。滤波器的每一级由一段微带线和交指电容构成。基于对每一级结构的分析,我们可以确定通带的范围。为了进一步提高带外的抑制性,对单级滤波器进行了周期性的级联。通过产生多个带外衰减极点来实现带外的宽带抑制。此滤波器3dB 截止频率3.67GHz,带内插损-0.9dB,带内回波损耗低于-13dB。通带到阻带的选择度为160dB/GHz。带外抑制从3.8GHz 到13.1GHz 低于-20dB。     

基于H型缺陷地结构的超宽带带通滤波器设计

微波频段的宽带滤波器一般具有通带插入损耗大,带外抑制性差等问题,为了解决这个问题,采用具有慢波效应的缺陷地结构(DGS)和缺陷微带结构(DMS),设计了一种新型微波频段的超宽带滤波器。分别利用电磁仿真软件HFSS和平面印制板技术对其进行建模仿真和实物加工。实测与仿真结果良好吻合,带内插入损耗优于1.64dB,回波损耗优于13.93dB,通带范围在2.75~8.3GHz,实现相对带宽100.45%,高低阻带均抑制在-10dB以下,且该滤波器结构紧凑,体积小。     

Synthesis and design of an LPF with wide-stop band and high rejection level

In this paper, a compact microstrip lowpass filter (LPF) is designed, analyzed, simulated, and tested. The proposed design that consists of a basic part in the central section of the structure and two parts of suppression of harmonics that are inserted in the first and last sections of the basic part, have wide-stop band, high suppression factor (−38 dB attenuation level from 2.4 GHz up to 27.4 GHz), low normalized size and sharp roll-off. The proposed LPF has a −3 dB cut-off frequency of 2.4 GHz, a wide stopband bandwidth around 11th harmonic suppression and an insertion loss less than 0.1 dB at passband. This filter has been fabricated and tested and good agreement is observed between the simulated and measured results.     

一种识别雷达用半集总参数LTCC双工器

介绍了一种基于低温共烧陶瓷(LTCC)工艺研制而成的小型化半集总高隔离度双工器.该双工器由L波段集总参数低通滤波器和X波段阶跃阻抗( SIR)分布参数带通滤波器组成.通过电磁仿真软件的仿真优化,实际加工滤波器的测试结果与软件仿真结果吻合.其中低通滤波器1dB截止频率为1.46GHz,带通滤波器中心频率为8.3GHz,1dB带宽为0.6GHz,通带内插损小于3.5dB,X波段端口对L波段端口隔离度大于60dB.该小型化LTCC双工器已成功应用于某毫米波战场识别系统的T/R组件中.