Realization of Multilayered Wide-Passband Bandpass Filter With Low-Temperature Co-Fired Ceramic Technology

This paper develops a new multilayered wide-passband bandpass filter with the assistance of low-temperature co-fired ceramic technology. The mutually inductive coupling between the input and output port of a low- and high-pass filter cascaded in the proposed filter is utilized as well. The results show that in the passband of 3.1–4.9 GHz, the measured insertion loss and return loss of this filter are less than 1.1 dB and greater than 18 dB, respectively. In addition, the insertion loss from dc to 2.76 GHz is greater than 20 dB, and the one from 5.8 to 12 GHz is greater than 30 dB.      

Design of Low-Temperature Co-Fired Ceramic Bandpass Filters With Modified Coupled Inductors

With the assistance of modified coupled inductors, novel multilayered bandpass filters are developed in this paper. Two or three transmission zeros appear on both sides of the passband skirt easily by incorporating the proposed structures. In order to fabricate compact multilayered bandpass filters, the low-temperature co-fired ceramic technology is also employed. In addition, the equivalent circuits of the modified coupled inductors are also proposed. Consequently, the measured results of the fabricated bandpass filters agree well with the responses of the full-wave electromagnetic design.     

A Microstrip Ultra-Wideband Bandpass Filter With Cascaded Broadband Bandpass and Bandstop Filters

This paper develops a novel ultra-wideband bandpass filter by cascading a broadband bandpass filter with another broadband bandstop filter. Properly selected impedances of transmission lines achieve broadband bandpass and bandstop filters and make independent designs possible. Detailed design and synthesis procedures are provided; moreover, agreement between measured and theoretically predicted results demonstrates feasibility of the proposed filter. Due to its simple structure, the ultra-wideband bandpass filter newly introduced in this paper is suitable for integration in the single-chipped circuit or implementation on printed circuit boards.     

UWB Bandpass Filter Using Microstrip-to-CPW Transition With Broadband Balun

A novel ultra-wideband bandpass filter (BPF) is presented using a back-to-back microstrip-to-coplanar waveguide (CPW) transition employed as the broadband balun structure in this letter. The proposed BPF is based on the electromagnetic coupling between open-circuited microstrip line and short-circuited CPW. The equivalent circuit of half of the filter is used to calculate the input impedance. The broadband microstip-to-CPW transition is designed at the center frequency of 6.85 GHz. The simulated and measured results are shown in this letter.     

Design of Symmetric Trisection Filters for Compact Low-Temperature Co-Fired Ceramic Realization

In this paper, the design of symmetric bandpass filters with cross-coupled trisections is discussed. The analysis and synthesis is done by well-known matrix manipulation of the lumped element equivalent circuit. The susceptance of the admittance matrix is split up into two separate matrices for capacitive and inductive contributions, which gives more insight into the manipulation of the matrix. Emphasis is put on design of a three-pole bandpass filter with two transmission zeros at the lower side of the passband. Novel solutions for the symmetric topology are derived, having either resonant main coupling or resonant cross-coupling. The potential of the novel topology is demonstrated by a compact realization of a wireless local area network filter at 2450 MHz in low-temperature co-fired ceramic technology. Good agreement between measured and computed results is obtained.      

带通与低通级联滤波器的设计

设计了一款应用于高铁系统上的双路同轴腔体滤波器,采用了带通与低通滤波器级联仿真方法,对其远端谐波进行有效抑制,从而提高滤波器带外的滤波性能。通过HFSS与Designer的联合仿真,用广义切比雪夫（General Chebyshev）滤波函数实现了中心频率为5 660 MHz,通带带宽为380 MHz,远端抑制达到25 dB的低插损高抑制的性能指标。最后对比了测试与仿真结果,得出带通滤波器级联低通滤波器可以实现带外高抑制的结论。     

Microstrip Parallel-Coupled Filters With Cascade Trisection and Quadruplet Responses

Microstrip parallel-coupled filters with generalized Chebyshev responses are presented. The basic structure of the proposed filter is a conventional parallel-coupled filter of which the physical dimensions can be easily obtained by the well-known analytical method. With the aid of the equivalent circuit corresponding to a conventional parallel-coupled filter, the relative insertion phase from source or load to each open end of resonators can be easily obtained by observing the two-port admittance matrix. Applying the cross coupling from source or load to a proper nonadjacent resonator, a trisection or a quadruplet coupling scheme can be realized with prescribed transmission zeros. More importantly, the proposed trisection can be designed to have a transmission zero on the lower or upper stopband by just adjusting the length of the cross-coupling strip. Using the proposed structure, the conventional time-consuming adjusting procedure to obtain initial physical dimensions of filters is no longer required. In this paper, a fourth-order parallel-coupled filter is used as the basic structure to demonstrate various combinations of transmission zeros. Simulated and measured results are well matched.      

基于HMSIW的宽带带通滤波器设计

为有效减小C波段基片集成波导的尺寸和插入损耗,提出了一种基于半模基片集成波导的紧凑型宽带带通滤波器。该滤波器引入由单个谐振槽和多个谐振槽组成的缺陷微带结构,并对其性能进行了研究。通过HFSS仿真验证,引入的缺陷微带结构,不仅可以减小插入损耗,而且实现传输零点的引入,改善了阻带特性。该方法设计的半模基片集成波导带通滤波器具有集成度高、体积小、成本低、制造方便等优点,在C波段卫星和雷达中得到了广泛的应用。     

Design and Development of Advanced Cavity-Based Dual-Mode Filters Using Low-Temperature Co-Fired Ceramic Technology for V-Band Gigabit Wireless Systems

In this paper, a novel concept of 3-D integrated -band dual-mode cavity filters, which permit the realization of a variety of quasi-elliptic responses by creating transmission zeros, has been demonstrated using multilayer low-temperature co-fired ceramic (LTCC) technology. A single-cavity resonator is designed to generate a degenerate resonance of two orthogonal modes ( and ), enabling dual-mode operation. The appearance and elimination of transmission zeros have been analyzed through the multipath coupling diagrams and lumped-element models. The quasi-elliptic dual-mode filters with the appropriate locations of the transmission zeros are then developed for receiver and transmitter channels of a -band transceiver module. Two pre-synthesized, dual-mode cavity filters are vertically stacked with two types of inter-coupling slots (1: rectangular, 2: cross) to realize the multipole filters for 60-GHz wireless local area network narrowband applications. These proposed filters are the first to be reported and have great potential to be integrated into miniaturized -band LTCC transceiver modules.     

Wideband Bandpass Filter With Reconfigurable Bandwidth

this letter proposes a novel building block for developing tunable wideband bandpass filters. The proposed circuit block mainly consists of short circuit coupled lines and short circuit stubs with pin diodes as tuning elements. This work aims to demonstrate reconfigurable bandwidth of this type of filter. Two filters are designed and fabricated; one can be switched between a fractional bandwidth (FBW) of 16.3% and 35% at a center frequency of 1.9 GHz, and the other can be switched from a FBW of 27.8% to 37.4% at a center frequency of 1.9 GHz. The insertion loss and return loss in the first filter range from 4.17 dB to 0.4 dB and 27.54 dB to 19.04 dB. The second filter exhibits an insertion loss ranging from 0.73 dB to 0.43 dB and a return loss range from 31.1 dB to 27.7 dB. The tested filters show good agreement with EM simulations.      

级联法实现宽带LC带通滤波器设计

利用高通、低通滤波器级联可以实现宽带带通滤波器,利用此方法设计了一个工作频段在100～400MHz的LC宽带带通滤波器。将所设计的截止频率为100MHz的高通滤波器HPF以及截止频率为400MHz的低通滤波器LPF级联实现滤波器的宽带化设计。通过分别对HPF和LPF设置带外陷波点使该带通滤波器具有较好的矩形系数、带外抑制效果。ADS仿真结果验证了理论设计的可行性,并通过优化使滤波器带宽达到4倍频程,带内平坦,输入、输出端口匹配良好,滤波器矩形系数达到1.2。     

Ka频段陶瓷基板微带带通滤波器设计分析

为满足微波电路小型化的发展要求,基于陶瓷基板设计了一款Ka频段的微带带通滤波器。分析了滤波器的电路设计原理及工艺设计方案,采用电路优化和三维全波仿真结合的方法对电路进行仿真。在优化后的版图基础上,通过改善膜层附着力、提高加工精度等方式对滤波器的加工进行控制。测试结果满足使用要求,证明了电路及工艺设计方案的正确性。     

Corrections to “Analysis and Design of New Single-to-Balanced Multicoupled Line Bandpass Filters Using Low-Temperature Co-Fired Ceramic Technology” [Dec 08 2902-2912]

In the above titled paper (ibid., vol. 56, no. 12, pp. 2902-2912, Dec. 08), there were several errors. Corrections are presented here.     

Compact Ultra-Wideband Bandpass Filter With EBG Structure

Two bandpass filters (BPFs) for ultra-wideband (UWB) applications are proposed using the uniplanar compact- electromagnetic bandgap (UC-EBG) and the foliated UC-EBG (FUC-EBG) structures for size reduction. The sizes of the proposed UWB BPFs are reduced by 20 ~ 22% compared to the conventional one with the microstrip multiple-mode resonator (MMR). Both EBG structures are shown to cause a slow-wave effect, which is required for compactness and the characteristic impedance Zc close to 50 Omega, which is needed for wideband match.     

A Microstrip Bandpass Filter With Ultra-Wide Stopband

This paper develops a novel microstrip bandpass filter with ultra-wide stopband. With the assistance of open stubs and interdigital capacitors, a very wide stopband with a sufficient rejection level can be achieved easily. Detailed design and synthesis procedures are provided. Moreover, the electromagnetic simulator IE3D is used, and the prototype of the bandpass filter is fabricated and measured. Good agreement between measured and theoretically predicted results demonstrates feasibility of the proposed filter.     

小型化三维发夹型LTCC宽带带通滤波器

利用低温共烧陶瓷(LTCC)工艺,通过通孔互联实现了三维结构的发夹型宽带带通滤波器。该结构将谐振单元的横向尺寸转移到z轴方向实现,有效减小了滤波器的尺寸并且谐振器间的耦合系数为传统结构的1.6倍。利用五个谐振器结构实现较宽的频带(>30%)和较好的选择特性。设计并实际制作了中心频率10 GHz的LTCC带通滤波器,3 dB带宽为8.8～12.1 GHz,实测指标与设计仿真结果较为吻合。     

Bandpass Filter With Dielectric Materials Used for Broadcasting Channel Filter

There are a lot of UHF television translator in Japan, and the equipment itself has been made small by using the recent solid state technology. Our paper reports the miniaturized channel filter with dielectric materials used for UHF television translator equipment in future.     

基于DGS结构的超宽带带通滤波器

基于双开口-互补开环谐振器的缺陷地结构(DGS),设计了一个结构紧凑的基片集成波导(SIW)超宽带带通滤波器。通过调整蚀刻在SIW底面的双开口-互补开环谐振器,SIW表面的共面波导与腔体之间的耦合,同时在阻带获得3个传输零点,以得到较好的频率选择性和良好的带外抑制。经过仿真优化及实物制作,测试结果表明,该滤波器工作在7.2GHz,相对带宽28%,带外抑制良好,仿真与测试结果吻合。     

Compact Ultra-Wideband Bandpass Filter With Improved Upper Stopband

In this letter, a design of a compact bandpass filter with wide upper stopband is presented for the ultra-wideband communication systems. The filter structure is composed of a modified square slot-line resonator with parallel microstrip feed lines. Improved upper stopband is obtained by exploiting the frequency dispersive coupling behavior between the feed lines and the resonator. Measurements show that the 20.9 dB upper stopband extends at least up to 20 GHz. Filter occupying area is 0.26lambdag times 0.28g, lambdag being the microstrip line guided wavelength at 6.85 GHz.     

Parallel-Coupled Coplanar-Waveguide Bandpass Filter With Multiple Transmission Zeros

A compact parallel-coupled coplanar-waveguide bandpass filter with good selectivity and stopband response is proposed. By using the quarter-wavelength resonators in implementation, the filter size can be reduced and no spurious passband is observed at twice the center frequency (2f₀). In addition, by suitably introducing the capacitive and inductive cross-coupling effects, four transmission zeros around the passband edges may be created for improving the filter selectivity. For design purpose, the equivalent-circuit models are also established. In this study, the compact fourth-order filter with multiple transmission zeros for improving the selectivity is implemented, and its stopband is extended up to 3.43f₀ with a rejection better than -30dB