低温共烧陶瓷(LTCC)四级低通滤波器设计

提出了一个结构紧凑,具有两个传输零点和优良频响特性的四级LTCC低通滤波器,并用场路结合的方法完成其设计。在经典切比雪夫四级低通滤波器的并联电容支路中增加一个电感,并进一步在1、3级串连电感支路之间引入交叉耦合,成功地在滤波器的通带附近产生了两个传输零点,形成了陡峭的衰减曲线。传输零点的位置可以通过改变谐振支路的L、C值或控制1、3级串连电感的间距来灵活移动,实现了通常需要五级椭圆函数低通滤波器才能达到的频响特性。提出的电路结构减少了电路元件的个数和复杂性,降低了滤波器的插入损耗。在分析集总参数等效电路的基础上,最后用电磁场仿真软件完成了整个电路的设计和频响分析。     

基于LTCC技术双零点带通滤波器的研究

基于LTCC技术提出了一种二阶带通滤波器,它是无源器件的重要结构。在设计上,得到一个中心频率为2.45 GHz、带宽为100 MHz的微波带通滤波器,传输零点频率为1.75 GHz和4.40 GHz。其尺寸为3 mm×3 mm×0.7 mm。它由电感电容元件构成6层立体结构,电磁与电路仿真结果吻合,表明所设计结构既减小了其体积,又得到了较好的频率效果。     

多传输零点LTCC带通滤波器的设计与仿真

设计了一个具有3个有限传输零点的小型化高阻带抑制三阶带通滤波器(BPF)。采用低温共烧陶瓷(LTCC)技术实现了一个中心频率在2.45GHz、带宽100MHz的带通滤波器,且具有优良的带外抑制性能,输入、输出驻波比低于1.12。通过在每个谐振腔上增加一个小型电感,在带外产生了多个有限传输零点,零点的位置可通过控制电感值的大小轻松移动。整个滤波器的外形尺寸为3.2mm×2.5mm×1.5mm,满足1210型号封装要求。     

Novel micromachined lumped band pass filter for 5.2 GHz WLAN applications

This paper describes the design, manufacturing and experiments of a lumped element band pass filter in a new topology. The design starts from a second order capacitive coupled resonator topology. An additional series inductor is inserted in the filter classical topology, for shifting two transmission zeros on the real frequency axes in the filter's band stop, to improve the high frequency response. Design equations for the new band stop resonance frequency are presented together with the analysis of the correspondence between the band pass and band stop attenuation vs. the quality factor of the shunt and series inductors used. The filter is supported on a 6.4 μm thin dielectric membrane, and is manufactured using silicon micromachining, in CPW technology. Measurements illustrated a minimum 2.75 dB insertion loss at 5.5 GHz in the band pass, and more than 40 dB attenuation, at 8 GHz.     

多传输零点LTCC带通滤波器的设计与实现

提出了一种阻带具有多个传输零点的带通滤波器设计方法,基于低温共烧陶瓷(LTCC)技术实现,可满足移动通信用滤波器小型化、高性能的要求。在电路设计中,通过改进滤波器谐振器结构,分别在阻带的低端近端、高端远端引入传输零点以提高带外抑制。借助三维仿真软件,进行指标、结构的仿真优化,设计并制作了一款尺寸为6 mm×3 mm×2 mm的LTCC滤波器,其中心频率f0=2.25 GHz,0.5 dB带宽不小于100 MHz,通带内损耗不大于1.8 dB,在1.33,1.78 GHz和二次谐波处均有传输零点。实测结果表明,该滤波器在阻带低端和二次谐波处有较好的抑制,因此其在移动通信系统中会有广泛应用。     

具有多传输零点的微波陶瓷滤波器设计

低温共烧陶瓷(LTCC)滤波器具有体积小、插损小和衰减大的特性,为了抑制其阻带信号,研究并设计了具有带外多个传输零点的多层LTCC带通滤波器,分析了传输零点对滤波器性能的影响.最后利用HFSS仿真软件设计了一个具有三级耦合谐振器、尺寸为2.5 mm×2.0 mm×0.9mm、中心频率为2.45 GHz的带通滤波器.仿真...     

一种基于模式匹配法的新型波导双工器设计北大核心CSCD

为进一步提高频带间隔离度,获得陡峭的抑制边带同时不增加体积,文中设计了一款新型的S频段波导双工器。在传统膜片式波导滤波器的基础上,低频滤波器提出了一种新型的波导CT型感性交叉耦合结构,高频滤波器引入非谐振腔结构,工作频段为2.025~2.12 GHz&2.2~2.3 GHz。根据其结构的不连续性,采用模式匹配法进行快速分析设计。该双工器在通带的高、低频带外均产生了传输零点,在2.2~2.3 GHz与2.025~2.12 GHz频段内,隔离度分别大于60 dB与90 dB,回波损耗大于20 dB。与同等性能的传统双工器相比,该双工器尺寸小、设计简洁,可在电子工程中广泛应用。     

基于微带SIR的单环及双环双模滤波器设计

采用阶跃阻抗方环代替传统的均匀阻抗方环结构,设计一种基于阶跃阻抗谐振器的微带双模滤波器。为增强滤波器的带外抑制和谐渡抑制特性,将双模滤波器从单环结构扩展到双环,两环之间通过偏馈微带线耦合。通过一个中心频率为2．5GHz、带宽约300MHz的滤波器设计和仿真,证实了基于SIR的方环双模滤波器不但具有尺寸上的优势,而且能通过级联获得传输零点多、带外抑制高、谐波抑制好的优点。     

A Miniaturized Conductor-Backed Slot-Line Resonator Filter With Two Transmission Zeros

In this letter, a miniaturized planar two-pole microwave filter with two transmission zeros is presented. The building block of this filter is a high-Q double spiral slot resonator backed by a conductor plane. The provision of a float back conductor plane allows vertical integration of this filter with other passive and active RF electronic components usually found in miniaturized wireless transceivers. The conductor plane also provides a coupling mechanism between the input and output of the filter giving rise to transmission zeros. It is shown that the location of transmission zeros can easily be adjusted and significant out-of-band rejection be achieved using only two miniaturized double-spiral resonators. The design procedure and fabrication of a two-pole filter operating at 2.11GHz is demonstrated and a very good agreement between measured and simulated results is shown     

多带外传输零点微带带通滤波器设计

设计了一种梳状微带平行耦合线窄带带通滤波器,仅应用两腔结构就实现了带外5个传输零点.通过微带线开路枝节,平行耦合线结构,以及馈电位置和两个梳状线谐振器之间的耦合,在通带附近引入了3个传输零点;四分之一波长平行耦合线接地短路结构,在带外高频产生额外两个传输零点,进而可有效抑制零点频率附近的杂波干扰.实测结果表明,设计的滤...     

结构紧凑的高选择性宽带滤波器

摘 要：为实现结构紧凑和高选择性的宽带滤波器,在传统平行耦合线结构的基础上,作了适当改进,设计了三种结构新颖的三线耦合结构,均能够实现具有三个传输零点的宽带响应,且其中两个零点分别紧靠通带的上下边缘。加工并测试了基于其中一种结构的宽带滤波器,工作频率为2.6GHz,3dB相对带宽为63%,三个传输零点分别位于1.46GHz,3.77GHz和5.13GHz,介质基板采用Rogers 4003,厚度0.813mm。实测结果与仿真结果吻合良好,验证了结构的有效性。     

S 波段高性能微型滤波器的研究

应用LTCC多层耦合带状线谐振器和交叉耦合传输零点原理,在改进的三维梳状带通滤波器结构中引入交叉耦合,增强非相邻谐振级间的交叉耦合;在2、4谐振级间引入Z字形导体层,通过调节Z字形控制传输零点位置;同时适当调节加载电容大小,有效减小了滤波器体积,实现了高次谐波抑制、边带陡峭和通带内线性相位.采用低温共烧陶瓷(LTCC)技术设计制作了中心频率为3GHz,通带为200MHz的微型带通滤波器.实验和仿真结果表明,该滤波器的中心频率插入损耗小于2.6dB,阻带抑制高于40dB,边带陡峭,尺寸仅为4.8mm×4.2mm× 1.5mm.成品率高达85％.     

L 波段带双零点的窄带LTCC 滤波器设计

本文应用LTCC 技术设计了一个L 波段二阶Chebyshev 窄带带通滤波器。该滤波器集成在9 层LTCC 介质中,采用等效集总元件（电容电感)结构,充分利用LTCC 的三维封装结构减小滤波器体积,通过谐振单元中集总元件的串并联产生两个带外传输零点,同时调整谐振单元耦合间距控制带宽。滤波器输入输出利用金属通孔将带状线过渡到微带上。滤波器（带过渡结构）的仿真结果为：中心频率1.42 GHz,1 dB 相对带宽2.1%,插入损耗通带内最低0.5 dB, 回波损耗优于20 dB,整个滤波器体积为：4.5×4×0.87 mm3。     

采用共面波导/微带耦合结构的超宽带带通滤波器的改进设计

本文提出了一种超宽带带通滤波器的改进设计方法,通过这种设计方法能够有效展宽阻带,实现谐波抑制的效果.该设计方式基于微带和共面波导(CPW)耦合的结构,其中,微带与输入,输出共面波导分别设计在介质基板的两个不同面上.本文在输入/输出端口附近的共面波导中心导带处做了改进,用于抑制高频段的谐波,从而在保证通带性能良好的基础上,有效抑制了寄生通带.文中给出了改进后滤波器的结构以及通过仿真和实验获得的性能参数,结果显示该滤波器具有良好的谐波抑制作用,使得阻带的高端达到20.0GHz,约为中心频率的3倍左右.     

A Dual-Band Combline Bandpass Filter Loaded by Lumped Series Resonators

This letter presents a dual-band combline bandpass filter (BPF) loaded by lumped series resonators. The proposed filter configuration can easily generate two desired passbands by controlling the resonant frequencies of the comblines as well as the series resonators. Furthermore, the skirt frequency characteristics between the two passbands are improved by transmission zeros introduced by source-load coupling via a lumped element capacitor. Two-pole dual-BPF with center frequencies of 1.2 and 1.54 GHz is designed and the measured results agree well with simulated results.     

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。     

Harmonic-suppression LTCC filter with the step-impedance quarter-wavelength open stub

An effective method to design a low-temperature co-fired ceramic RF bandpass filter with suppression of the harmonic frequency is demonstrated in this paper. The second harmonic, which appears in the frequency band of 4.8-5.0 GHz, is very significant and should be reduced in the 2.4-GHz wireless local area network and Bluetooth application. This feature of harmonic frequency suppression is very important in a communication system to improve linearity, output power, intermodulation performance, etc. The harmonic-suppression filter can be easily obtained by adopting the characteristic of equivalent quarter-wavelength resonators. The detailed three-dimensional layout of each layer is disclosed. By analyzing the influences of the dielectric constant and layer thickness of a ceramic sheet by electromagnetic simulation, the optimal condition for the filter design can be obtained. The measured results agree well with the simulation.     

基于LTCC技术的椭圆函数低通滤波器设计

随着无线通信领域的快速发展,人们对微波滤波器性能的要求也越来越高。文章根据滤波器的分类和特点,研究了集总元件滤波器引入传输零点的规律和方法,分析并对比了三种不同类型低通滤波器的衰减特性。根据设计指标要求,基于LTCC技术设计了一款高性能小型化的椭圆函数七阶低通滤波器。滤波器的等效电路包括串联支路中的4个电感和并联支路中的3个LC谐振腔,共10个元件。通过对滤波器模型物理结构的优化,减小了滤波器内部元件间的寄生耦合效应,并在阻带中成功引入了传输零点,改善了滤波器的性能。     

Microstrip Coupled-Line Lowpass Filter with Wide Stopband for RF/Wireless Systems

We present the design of a compact microstrip lowpass filter with a wide stopband which is up to ten times the cutoff frequency. The filter is based on a coupled-line configuration and shunt open stubs. The open stubs create additional transmission zeros, which are used to extend the stopband of the filter without any additional components or cascaded units. A prototype lowpass filter with a 3 dB cutoff frequency of 0.428 GHz and a 15 dB stopband extended up to 4.77 GHz is fabricated to validate the theoretical predictions.     

Low-loss and high-selectivity bandpass filter with harmonic suppression and piezoelectric transducer tuning

A low-loss and high-selectivity bandpass filter with harmonic suppression and piezoelectric transducer (PET) tuning is presented. At the 3.5 GHz passband, the insertion loss is 1.48 dB, and the transmission zeros at 3.05 and 4.08 GHz have a rejection of 55 dB. The rejection at the 7 GHz second harmonic is 50 dB. A PET tunes the bandstop sections to obtain a tunable suppression (>45 dB) around the second harmonic from 5.35 to 7.8 GHz.