微带抽头线发夹型带通滤波器的设计及优化

介绍一种用ADS( Advanced Design System)软件进行设计和优化微带抽头线发夹型带通滤波器.详细地给出了设计步骤及其各个参数的确定.以一个中心频率为4.8 GHz,带宽为200 MHz的微带带通滤波器的设计及优化为例,给出了仿真结果,并进一步给出了Momentum仿真结果.     

一种基于LTCC技术的UHF波段高性能带通滤波器

介绍了一种基于低温共烧陶瓷(LTCC)技术实现的UHF波段高性能带通滤波器,其中心频率为490MHz。由于该滤波器频率较低、波长较长,为了减小滤波器的尺寸,本设计采用了半集总半分布结构来实现。通过增加传输零点和滤波器级联技术大大提高了滤波器的带外抑制度。借助三维仿真软件进行优化仿真,设计出了一个中心频率为490MHz、带宽为100MHz、带外抑制优于40dB、尺寸仅为6.4mm×4.0mm×1.5mm的带通滤波器。实测结果与电磁仿真结果较为吻合。     

超宽带高抑制无反射带通滤波器的设计

为了提高无反射带通滤波器的带宽和衰减,设计一款基于集成无源器件技术的小型化、超宽带、高带外抑制的无反射带通滤波器。该滤波器由无反射低通滤波器、无反射高通滤波器和匹配电路级联而成,无反射低通、高通滤波器级联可实现超宽带,通过在匹配电路的上下频带各引入一个零点的方法,将滤波器的带外抑制峰值提高到了40 dB。通过HFSS软件在硅衬底上对其进行建模仿真,最终实现了所需的无反射带通滤波器。该滤波器的中心频率f_0为2.43 GHz,中心频率处的插入损耗为1.17 dB,BW_(-3dB)≤1.86 GHz,带外抑制≥40 dB,回波损耗在12 dB左右,整体尺寸仅为2.65 mm×1.25 mm。三维电磁场仿真结果表明,该款无反射带通滤波器的相对带宽为76.5%,衰减为40 dB。     

一种LC型CMOS射频带通滤波器及其自动调谐

介绍了一种二阶可调谐CMOS LC型射频带通滤波器及与其匹配的压控振荡器设计.品质因数很高而且可以通过负电导发生电路调谐.目标频率由一组分立的亚波段组成,通过电容阵列来控制.仿真结果表明,滤波器采用TSMC 0.18 μm CMOS 工艺,工作电压3.3 V,中心频率调谐范围为2.05 Hz至2.38 GHz.文中简单介绍了锁相环自动调谐系统.为了与滤波器进行匹配,振荡器是基于滤波器的原型设计的,仿真结果表明它们匹配良好.     

基于反耦合线的宽带带通滤波器设计

提出一种新型的基于反耦合线结构的宽带带通滤波器,该滤波器结构由一段弯折型反耦合线以及一个开路传输线枝节组成。采用奇偶模分析法对所提出的滤波器结构进行分析并进行仿真。结果表明,选择适当电路参数,该滤波器可以产生六个传输零点。对设计的两个带通滤波器(Filter-A 和 Filter-B)进行仿真和实测。结果如下：中心频率为 3 GHz 时,Filter-A 百分比带宽为 47%,Filter-B 为 40%,结果表明在带内插损较低、群延迟较好的情况下,该类滤波器在百分比带宽上有一定优势。     

X波段发卡型及其改进型宽带微带带通滤波器

采用发卡型及其改进型结构,在X波段设计了一组宽频带微带带通滤波器。发卡型结构是由二分之一波长的谐振单元变化为"U"结构而来,发卡改进型结构则是将发卡型的"U"结构拉直演变而来,其增加了电容缝隙耦合及开路支节数。仿真结果表明:该组滤波器绝对带宽为1.8GHz,带内损耗低于1.1dB,偏离中心频率-2.5GHz和+2.5GHz处,带外抑制分别大于30dB和48dB。采用理论分析与软件仿真相结合的方法,研究了两种滤波器的开路支节长度与中心频率的关系以及耦合间距对带宽的影响。实测数据与仿真结果一致性较好,验证了该设计的正确性。     

基于ADS的平行耦合微带线带通滤波器的设计及优化

介绍一种借助ADS(Advanced Design System)软件进行设计和优化平行耦合微带线带通滤波器的方法,给出了清晰的设计步骤,最后结合设计方法利用ADS给出一个中心频率为2.6 GHz,带宽为200 MHz的微带带通滤波器的设计及优化实例和仿真结果,并进一步给出电路版图Momentum仿真结果.仿真结果表明:这种方法是可行的,满足设计的要求.     

基于LTCC技术的带通滤波器分析与设计

文章介绍了一种中心频率为2.45GHz的LTCC多层带通滤波器的设计方法。利用二阶耦合谐振带通滤波器的原型,通过一种分析合成带通滤波器的方法,将原型电路等效为4个L型匹配电路,设定其中两个匹配品质因子,经过推导并进行参数值取舍后,即可得到原型电路中所有元件的合成公式以及电路中各器件的参数值。利用三维电磁场仿真软件HFSS建立模型,可以将电磁模拟结果与电路仿真结果较好地吻合。最后采用标准LTCC工艺实现出尺寸为3.6mm×2.9mm×1.1mm的带通滤波器。     

一种基于阶跃阻抗波导带通滤波器的设计

利用阶跃阻抗谐振器(SIR)结构设计波导带通滤波器。该方法减小体积,又可以将杂散谐振频率向高端推移,从而增加阻带宽度,使得结构的设计获得很大的自由。最后,利用电磁场仿真软件对结构尺寸进行优化仿真,并实际制作一个中心频率为780 MHz(通带差损小于0.7 dB)的SIR带通滤波器。实测结果和仿真结果吻合良好,达到预计指标参数。该滤波器具有体积小,结构简单易于加工等优点。     

一种半集总微波带通滤波器的设计

本文设计了一种适用于阵列天线的带通滤波器,主要用于抑制杂波干扰。该滤波器以传统椭圆函数滤波器设计理论为基础,并对输入输出端口进行高低通包络匹配,从而解决了椭圆函数滤波器带外抑制平缓的问题 。为了满足滤波器设计指标的要求,电路采用半集总参数思路实现。文中给出了该滤波器的设计过程及实际测量结果。实测结果和仿真结果相符合,满足技术指标要求。     

Optimized E-plane bandpass filters with improved stopbandperformance

A computer-aided synthesis technique for E-plane bandpass filters with improved stopband performance is developed. An optimization procedure based on equal ripple optimization is adopted. The design of a symmetrical E-plane bandpass filter with improved stopband performance is considered; higher order mode interaction between E-plane discontinuities is included in the design. The predicted filter performance shows improved stopband performance and reduced filter dimensions compared with conventional E-plane bandpass filters. The validity of the method is confirmed by the measurement of a fabricated five resonator E-plane bandpass filter with improved stopband performance     

宽阻带阶跃阻抗发夹线带通滤波器设计

提出了新的抑制微带带通滤波器寄生通带的方法。这种方法通过级联阶跃阻抗发夹线谐振器构成的椭圆函数低通滤波器于带通滤波器的输入/输出端,显著改善了后者的阻带抑制特性。本文基于新的等效电路模型,推导出了此类低通滤波器的阻带传输零点位置。设计了L波段宽阻带阶跃阻抗发夹线带通滤波器验证了理论分析和设计过程的正确性。     

Reflective Amplified Recirculating Delay Line Bandpass Filter

A new microwave photonic filter structure that can achieve a high factor, high stopband rejection, and high skirt selectivity bandpass filter response simultaneously is presented. It is based on reflecting the signal back into a single amplified optical recirculating delay line and comprises coherent summation of the multiple signals that constitute each tap and incoherent summation of the successive taps. This introduces a new class of filter operation and effectively enables the realization of a higher order bandpass filter characteristic in a very simple structure. Experimental results are presented that demonstrate a multiple-tap high- bandpass filter response that also displays high stopband rejection level and high skirt selectivity.     

高阻带抑制LTCC 滤波器的设计与实现*

提出了一种基于LTCC技术的新型高阻带抑制带通滤波器的实现方法.采用在并联谐振器的圆柱形电感之间引入感性耦合,在高阻带产生一个传输零点,并且能实现非常好的阻带衰减性能.本文对传统的梳状线带通滤波器结构进行改进,利用过孔的寄生电感效应,将过孔用作谐振杆,明显减小了器件的尺寸.并且通过利用空间耦合的寄生效应,实现滤波器的阻带高抑制传输零点,以满足了对特殊频点高抑制的要求.运用该方法设计了中心频率1.65 GHz,通带200MHz,带外2GHz处衰减大于60dBc的五级带通滤波器.实物测试结果和全波电磁仿真结果吻合较好.     

A Wideband and High Rejection Multimode Bandpass Filter Using Stub Perturbation

A novel multimode bandpass filter with high and wide rejection band is proposed by using an open stub. The open-stub has two functions in the filter: (1) perturbation for the multimode operation and (2) zero point generation at the stopband for the stopband control. With proper input/output coupling, additional two poles, i.e., four poles, can be generated for the proposed filter structure. The design is then verified by experiment. The single structure four-mode filter has low insertion loss, good stopband performance, and compact size and linear phase.     

Photonic bandpass filters with high skirt selectivity and stopband attenuation

A new photonic signal processor topology that simultaneously achieves both a high-Q and a high skirt selectivity and stopband attenuation filter response is presented. It is based on a novel dual-cavity bandpass optical structure in which two pairs of active fiber Bragg grating cavities are used with an optical gain offset to control the poles and stopband attenuation characteristics of the filter. This concept enables a large improvement in the filter stopband attenuation, rejection bandwidth, and skirt selectivity to be realized. Measured results demonstrate both a narrow bandpass bandwidth of 0.4% of center frequency and a skirt selectivity factor of 16.6 for 40 dB rejection, which corresponds to a 6.5-fold improvement in comparison to conventional single cavity high-Q structures. To our knowledge, this is the best skirt selectivity reported for a photonic bandpass filter to date. The new photonic filter structure has been experimentally verified and excellent agreement between measured and predicted responses is shown.     

Ultra Wideband Bandpass Filter Using Embedded Stepped Impedance Resonators on Multilayer Liquid Crystal Polymer Substrate

This letter proposes an ultra wideband (UWB) bandpass filter (BPF) based on embedded stepped impedance resonators (SIRs). In this study, broad side coupled patches and high impedance microstrip lines are adopted as quasi-lumped elements for realizing the coupling between adjacent SIRs, which are used to suppress stopband harmonic response. An eight-pole UWB BPF is developed from lump-element bandpass prototype and verified by full-wave simulation. The proposed filter is fabricated using multilayer liquid crystal polymer (LCP) process and measured using vector network analyzer. Good agreement between simulated and measured response is observed. The measurement results show that the fabricated filter has a low insertion loss of 0.18 dB at center frequency 6.05 GHz, an ultra wide fractional bandwidth of 127.3% and excellent stopband rejection level higher than 32.01 dB from 10.9 to 18.0 GHz.      

Tunable photonic bandpass filter with high-frequency response performance

A continuously tunable RF/microwave photonic bandpass filter that simultaneously achieves high skirt selectivity and high stopband attenuation is presented. It is based on controlling the signal polarisation state in a reflective amplified recirculating delay line loop with a polariser at the output. A technique to overcome the phase noise limitation in the structure is also presented. Experimental results demonstrate continuous tuning of the high-performance photonic bandpass filter and a continuously tunable photonic bandpass filter with a low-noise performance.     

一种具有陡峭边带的宽带带通滤波器设计

基于一种新型的多模谐振器设计了一款宽带带通滤波器,该多模谐振器由鱼骨形谐振器及中心加载倒T形谐振器构成。滤波器的中心频率位于2.47 GHz,相对带宽为100%。滤波器具有极高的频率选择性,其边带滚降速度分别为232 dB/GHz和168 dB/GHz。此外,滤波器还具有较低插入损耗0.4 dB,紧凑的电路尺寸以及宽阻带抑制能力。     

Wideband coplanar-waveguide bandpass filters with good stopband rejection

Wideband coplanar-waveguide (CPW) bandpass filters based on the cascade of CPW lowpass and highpass periodic structures are proposed. The upper and lower stopband characteristics of proposed bandpass filter can be easily designed by separately adjusting the lowpass and highpass sections, respectively. Specifically, two wideband CPW bandpass filters with sharp roll-off at passband edges and good stopband rejection are demonstrated.