低损耗衬底上实现无源低通滤波器

分析比较了不同种类衬底上无源器件(片上电感和电容)的损耗机理,在OPS(氧化多孔硅)和HR(高阻硅)低损耗衬底上分别实现了片上低通滤波器.为了研究衬底损耗,设计了平面螺旋电感,其Q值在两种衬底上的仿真结果都超过了20.在OPS衬底上的低通滤波器实测-3dB带宽为2.9GHz,通带插入损耗在500MHz为0.87dB;在HR衬底上的低通滤波器实测-3dB带宽为2.3GHz,通带插入损耗在500MHz为0.42dB.     

基于LTCC工艺的低通滤波器设计与实现

为了实现具有高Q值电容电感的小型化滤波器,本文采用低温共烧陶瓷(LTCC)工艺分别构建了垂直螺旋式电感和垂直直插式电容,利用电容电感的参数提取公式并结合HFSS软件进行优化仿真,获得具有高Q值的电容电感模型,并根据此模型来设计一款DC-500MHz小型化低通滤波器。最终经过实际测试结果表明该低通滤波器性能为：在0~500MHz插入损耗优于-0.5dB,回波损耗优于-18dB,带外抑制在1GHz处有-30dB,在1.5GHz处有-50dB。 关键词：低通滤波器;低温共烧陶瓷工艺;高Q值;小型化     

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.     

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.     

基于MMIC工艺的片上射频LC无源滤波器

设计、制作了几种基于MMIC工艺的片上LC低通/带通滤波器并进行了测试.测试结果表明,一个3nH的MMIC电感在6.8GHz下品质因数达到13.8.自谐振频率达到15.5GHz;制作的LC低通/带通滤波器的截止频率或中心频率与设计偏差很小,分别为2%和3.3%;低通滤波器在各自通带内的插入损耗小于3dB,带通滤波器在中心频率的插入损耗为7.2dB.     

基于MMIC工艺的片上射频LC无源滤波器

设计、制作了几种基于MMIC工艺的片上LC低通/带通滤波器并进行了测试. 测试结果表明,一个3nH的MMIC电感在6.8GHz下品质因数达到13.8,自谐振频率达到15.5GHz;制作的LC低通/带通滤波器的截止频率或中心频率与设计偏差很小,分别为2%和3.3%;低通滤波器在各自通带内的插入损耗小于3dB,带通滤波器在中心频率的插入损耗为7.2dB.     

宽阻带平面低通滤波器的设计

低通滤波器是通信系统中关键的器件之一,常作为选频器件用来抑制干扰信号和谐波信号,因此低通滤波器阻带带宽成为关键指标.常见的平面低通滤波器采用短截线(分支线)或高低阻抗线结构,这些结构的低通滤波器阻带不够宽,一般在截止频率的2倍频或3倍频处出现寄生通带.本文使用等效的T形节替代低通滤波器中的串联传输线的方式实现了带阻滤波器嵌入到低通滤波器内部,既对低通滤波器的阻带上任意频段出现的寄生通带进行了抑制,又不影响低通滤波器的通带内性能,并给出等效T形节的综合设计公式.此结构综合设计方法严谨简单、易于平面电路实现,制作出来改进的低通滤波器对3倍频寄生通带进行抑制,扩宽了阻带带宽到4个倍频程以上,测试结果:通带带宽0~3GHz,通带插入损耗小于0.5dB,带外抑制3.6~12GHz大于60dB.     

低阻硅衬底上形成的低损耗共平面波导传输线

在厚膜多孔硅 (PS) /氧化多孔硅 (OPS)衬底上 ,结合聚酰亚胺涂层改善表面 ,研制低损耗、高性能射频 (RF) /微波 (MW)共平面波导CPW(CoplanarWaveguide) .通过在N和P型硅上形成不同厚度PS膜 ,并对其上的CPW进行分析比较 ,厚膜PS与石英的共面波导插入损耗非常接近 ,远小于在 2 0 0 0Ω·cm高阻硅上形成的多晶硅 -氧化硅组合衬底 :在 0 33GHz范围 ,插入损耗小于 5dB/ 1.2cm ;33 4 0GHz范围 ,小于 7.5dB/ 1.2cm .     

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。     

基于非对称互补开口谐振环的基片集成波导带通滤波器

本文提出了一种新颖简单的结构用于设计具有良好带外抑制能力的单通带和双通带滤波器。在矩形基片集成波导谐振腔的接地面上设计了一对非对称的互补谐振环,使其在单通带滤波器下作为一个微扰元件,在双通带滤波器下作为一个谐振元件。本文提出了一种在不改变整个腔体尺寸的前提下,仅通过调整非对称互补谐振环的相对位置来实现单通带和双通带转换的新方法。此外,通过抑制高阶模式实现宽阻带性能,并通过引入有限的传输零点来提高带外抑制能力。为了验证该设计的可行性,本文设计,加工并测试了中心频率为11.075GHz,带宽为750MHz的单通带滤波器和中心频率为11.45GHz,14.25GHz,带宽均为500MHz的双通带滤波器。测量结果表明通带内回波损耗均大于13dB,插入损耗小于1.5dB。测试结果与仿真结果基本一致。     

Miniature and tunable filters using MEMS capacitors

Microelectromechanical system (MEMS) bridge capacitors have been used to design miniature and tunable bandpass filters at 18-22 GHz. Using coplanar waveguide transmission lines on a quartz substrate (/spl epsiv//sub r/ = 3.8, tan/spl delta/ = 0.0002), a miniature three-pole filter was developed with 8.6% bandwidth based on high-Q MEMS bridge capacitors. The miniature filter is approximately 3.5 times smaller than the standard filter with a midband insertion loss of 2.9 dB at 21.1 GHz. The MEMS bridges in this design can also be used as varactors to tune the passband. Such a tunable filter was made on a glass substrate (/spl epsiv//sub r/ = 4.6, tan/spl delta/ = 0.006). Over a tuning range of 14% from 18.6 to 21.4 GHz, the miniature tunable filter has a fractional bandwidth of 7.5 /spl plusmn/ 0.2% and a midband insertion loss of 3.85-4.15 dB. The IIP/sub 3/ of the miniature-tunable filter is measured at 32 dBm for the difference frequency of 50 kHz. The IIP/sub 3/ increases to >50 dBm for difference frequencies greater than 150 kHz. Simple mechanical simulation with a maximum dc and ac (ramp) tuning voltages of 50 V indicates that the filter can tune at a conservative rate of 150-300 MHz//spl mu/s.     

Eight-channel flat spectral response arrayed-waveguide multiplexer with asymmetrical Mach-Zehnder filters

An eight-channel flat spectral response arrayed-waveguide grating (AWG) multiplexer with asymmetrical Mach-Zehnder filters has been fabricated on the planar lightwave circuit (PLC). The monotonic spectral loss characteristics of AWG have been canceled by the opposite spectral response in the asymmetric MZ filter. The 1.5 dB bandwidth of 141 GHz and 3 dB bandwidth of 159 GHz are obtained for the 200 GHz channel spacing. The 1.5 dB bandwidth becomes 1.8 times wider than that of the conventional AWG. Crosstalks to neighboring and all other channels are less than -24 dB and the on-chip insertion losses range from 7.0 to 7.4 dB, respectively.     

A UHF current-mode continuous-time band-pass delta sigma modulator using fully balanced active inductor

This paper introduces a 2 GHz continuous-time (CT) fourth order current-mode (CM) band-pass 0.18 μm CMOS delta sigma modulator (DSM) utilizing a fully balanced active inductor. The proposed active inductor takes advantage of positive feedback topology and features accurate loss compensation as well as independent tunability of quality factor and resonant frequency. Based on this active inductor, a CM Ultra High Frequency (UHF) resonator is also proposed, exhibiting a very small on-chip area. Moreover, a high speed CM quantizer working with one single clock is brought into eliminate the error introduced by clock generators. The post layout simulation of the DSM exhibits a peak SNDR of 43.6 dB at 500 MHz with a 40 MHz signal bandwidth while the center frequency can be tuned between 450 and 500 MHz. The measured results give an averaged SNDR of 33 dB with 40 MHz signal bandwidth, where the center frequency is tunable from 300 MHz to 350 MHz. This design consumes only 45 mW under 1.8 V power supply and occupies an area of 0.133 mm².     

Flat spectral response arrayed-waveguide grating multiplexer withparabolic waveguide horns

An eight-channel flat spectral response arrayed-waveguide grating multiplexer with parabolic waveguide horns has been fabricated on a planar lightwave circuit (PLC). A double-peaked intensity distribution is formed at the slab interface by the parabolic waveguide horn. A 1 dB bandwidth of 98 GHz, 3 dB bandwidth of 124 GHz and 20 dB bandwidth of 196 GHz are obtained for 200 GHz channel spacing. The crosstalk to neighbouring channels is less than -27 dB and the on-chip insertion losses range from 6.1 to 6.4 dB, respectively     

Design of 50–70 GHz Planar Wideband Bandpass Filter on Liquid Crystal Polymer Substrate

In this paper, the authors propose a novel and compact 50-70 GHz planar microstrip bandpass filter, possessing sharp-rejection, low insertion-loss and wide-band characteristics, based on Liquid Crystal Polymer (LCP) substrates. The filter is fabricated on LCP substrates by using standard processing technologies. The proposed filter exhibits a return loss level better than 10 dB, an insertion loss of 5 dB and a 3-dB bandwidth of 30%.The measured and simulated results show good agreement, proving that LCPs are potential and very promising materials for flexible millimeter-wave substrate applications.     

Ultra-wideband bandpass filter using hybrid quasi-lumped elements and defected ground structure

A compact planar microstrip ultra-wideband (UWB) bandpass filter is presented. The proposed UWB filter is realised by cascading a highpass filter (HPF) and a lowpass filter (LPF). Additional U-slot defected ground structure is adopted to improve the attenuation performance in the stop band. The HPF consists of inter-digital capacitors and a short-circuited stub. The LPF achieved by a hybrid microstrip and four backside slots on the ground plane is equivalent to a typical 9-pole stepped-impedance LPF. Combining these two structures, a new UWB bandpass filter is fabricated and measured. Measured results show that the proposed bandpass filter has a wide bandwidth from 3.1 to 11 GHz, and insertion loss is less than 1.2 dB over the most central passband. It also achieves a wide stop band with 20 dB attenuation up to 20 GHz.     

Multipassband electronically tunable magnetostatic wave filter

A new design for a multipassband microwave filter based on magnetostatic waves propagating in a multilayer planar ferrite structure is described. The experimentally realised filter had two passbands of 10 MHz bandwidth and 5-6 dB insertion loss separated by 400 MHz, and was tuned with an external magnetic field over the 2.5-4 GHz range.<>     

Eight-Way Substrate Integrated Waveguide Power Divider With Low Insertion Loss

We describe a compact radial cavity power divider based on the substrate integrated waveguide (SIW) technology in this paper. The equivalent-circuit model is used to analyze the multiport structure, and a design procedure is also established for the structure. An eight-way C-band SIW power divider with low insertion loss is designed, fabricated, and measured. Good agreement between simulated and measured results is found for the pro posed power divider. The measured minimum insertion loss of the eight-way power divider is approximately 0.2 dB and return loss is approximately 30 dB at 5.25 GHz. The measured 15-dB return-loss bandwidth is found to be approximately 500 MHz, and its 1-dB insertion-loss bandwidth is approximately 1.2 GHz. Furthermore, the isolations between the output ports of the eight-way power divider are also discussed.     

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.