Bandpass Filter (bandpass + filter)

Distribution by Scientific Domains

Kinds of Bandpass Filter

  • dual-band bandpass filter
  • microstrip bandpass filter

  • Terms modified by Bandpass Filter

  • bandpass filter design

  • Selected Abstracts


    32-GHz dual-termination coupled CPW bandpass filter on HR-SI

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2008
    Xi Li
    Abstract Bandpass filter is an important device in portable communication and other RF systems. A dual-termination coupled coplanar waveguide (CPW) bandpass filter (BPF) has been designed by HFSS. This dual-termination coupled structure improves the coupling capacitances between the central metal and the matching transmission lines so that the insertion loss can be reduced. The filter has been fabricated on a high resistivity silicon substrate (, , 1000 , cm) with 1 ,m SiO2. It has ,2.16-dB low insertion loss at peak transmission of about 32 GHz. This filter shows good s-parameter characteristics and it is attractive for RF ICs. 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1705,1706, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23464 [source]


    Light-emitting diode-induced fluorescence detection of native proteins in capillary electrophoresis

    ELECTROPHORESIS, Issue 21 2005
    Chanan Sluszny
    Abstract A continuous-wave 280 nm light-emitting diode (LED) was used as the excitation source for native fluorescence detection of proteins in CE. The operating current and temperature of the LED were optimized in order to achieve high luminescence power. It was found that a forward current of 30,mA and a temperature of approximately 5C gave the best S/N. By using a set of two ball lenses to focus light from the LED, we achieved a spot of approximately 200,,m with a power of 0.1,0.2,mW on the detection window. Fluorescence was collected with a ball lens at 90 angle through a bandpass filter onto a photomultiplier tube. In CZE an LOD of 20,nM for conalbumin was reached. In capillary gel electrophoresis all eight proteins from a commercial standard kit were detected with high S/N. For a 10,,g/mL total protein mixture, S/N was better than 3 for all proteins in solution. Further improvement in LOD should be possible on utilization of an LED with higher luminescence power. [source]


    Realization of log-domain high-order transfer functions using first-order building blocks and complementary operators

    INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 1 2007
    Costas Psychalinos
    Abstract High-order log-domain filters could be easily designed by using the functional block diagram (FBD) representation of the corresponding linear prototype and a set of complementary operators. For this purpose, lossy and lossless integrator blocks have been already introduced in the literature. Novel first-order log-domain highpass and allpass filter configurations, which are fully compatible with the already published integrator blocks, are introduced in this paper. These are realized using integration and subtraction blocks or a novel differentiation configuration. As a result, a complete set of first-order building blocks would be available for synthesizing any arbitrary high-order transfer function. In order to verify the correct operation of the proposed structures, the performance of the introduced highpass filters was evaluated through simulation results. In addition, a fifth-order log-domain bandpass filter was designed and simulated using one of the introduced first-order highpass filter configurations. Copyright 2006 John Wiley & Sons, Ltd. [source]


    A bandpass filter with adjustable bandwidth and predictable transmission zeros

    INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 2 2010
    Li Zhu
    Abstract In this article, a microstrip bandpass filter with an adjustable bandwidth and predictable transmission zeros is proposed. The proposed filter is implemented by combining two hairpin edge-coupled resonators with interdigital capacitors. Compared to typical edge-coupled filters, the proposed filter provides a wider bandwidth resulting from a higher coupling strength between its resonators. To further increase the coupling and consequently the bandwidth, a pair of etched slots in the ground plane is used. By adjusting the geometrical parameters of the interdigital capacitors and etched slots, the bandwidth can be easily adjusted. The filter features two transmission zeros, which are determined by means of the semi-analytical model developed as part of this work. Furthermore, the proposed filters can be cascaded to obtain a sharper cutoff frequency response. Frequency responses of the filters from measurements are in good agreement with those simulated using IE3D in the 5,9 GHz range. 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010. [source]


    Microstrip dual-band bandpass filters using parallel-connected open-loop ring resonators

    INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 3 2008
    Lung-Hwa Hsieh
    Abstract This article proposes a microstrip dual-band bandpass filter that uses parallel-connected open-loop ring resonators. Compared to many microstrip dual-band filters, the advantages of using microstrip open-loop ring resonators are easy calculation (half-guided-wavelength), easy fabrication (equal width for all 50-, lines and without grounding holes), and direct connection to external feed lines (reducing insertion loss caused by gap couplings). Another advantage of the filter is an asymmetrical feed on the ring resonator that provides sharp rejections at its adjacent bands. The input and output matches of resonators to the external feed lines are derived using a simple transmission-line theory. The results of the derivation provide a simple design rule for filter designers. Simulated and measured results are presented with good agreement. The filter has minimum insertion loss of 1.25 dB at 1.85 GHz and 1.6 dB at 2.33 GHz. The 3-dB fractional bandwidths are 5.9% for the 1.9-GHz bandpass filter and 4.7% for the 2.4-GHz bandpass filter, respectively. 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008. [source]


    Low-spurious-response coaxial-line BPF with saucer-loaded stepped-impedance resonators designed with mode-matching technique

    INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 3 2004
    Hiromitsu Uchida
    Abstract A novel stepped-impedance resonator with a thin metal saucer is proposed in order to reduce spurious-response levels in a coaxial-line bandpass filter (BPF). In designing the BPF, the mode-matching technique is employed for fast and accurate calculation of coaxial-line discontinuities. A prototype BPF obtains a spurious-response level of less than ,55 dB in the frequency band from 2f0 to 9f0, where f0 is the pass-band center frequency. 2004 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14: 227,235, 2004. [source]


    Distributed MEMS transmission lines for tunable filter applications

    INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 5 2001
    Yu Liu
    Abstract This paper describes the design and fabrication of a distributed MEMS transmission line (DMTL), used to realize a transmission-line with a voltage-variable electrical length for microwave circuits. The DMTL is a coplanar waveguide periodically loaded with continuously-variable MEMS capacitors. A tunable bandpass filter was designed and fabricated on 700 ,m thick glass substrates using three capacitively coupled DMTL sections as variable shunt resonators. The measured results demonstrate a 3.8% tuning range at 20 GHz with 3.6 dB minimum insertion loss. Issues for future improvement are discussed. 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 254,260, 2001. [source]


    VHF high-power tunable RF bandpass filter using microelectromechanical (MEM) microrelays

    INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 5 2001
    Robert D. Streeter
    Abstract A VHF RF bandpass filter tuned through the use of MEM microrelays was operated at a 25 W RF power input level. The filter insertion loss was less than 1 dB at the tuned frequencies of operation, and the filter operating Q was about 10. The MEM microrelays were life tested for 53 million operating cycles at 25 W RF power, and no significant degradation to the contacts was noted. The development of the microrelay and the use of a CAE tool in the filter development are discussed. 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 261,275, 2001. [source]


    Single-stage gain-clamped L-band EDFA with C-band ASE self-oscillation in ring cavity

    LASER PHYSICS LETTERS, Issue 2 2008
    M.A. Mahdi
    Abstract We demonstrate single-stage gain-clamped L-band Er3+ -doped fiber amplifier (EDFA) utilizing self-oscillation modes as the control light. The amplifier structure exploits the characteristics of C/L-band coupler to isolate between lasing modes and L-band signal. The self-lasing cavity modes are obtained without any tunable bandpass filter in the loop and generated from the amplified spontaneous emission in the C-band region. The amplifier configuration has lower noise figures as opposed to a dual-stage partially gain-clamped amplifier. The gain and noise figure fluctuations are less than 0.4 dB in the gainclamping region. The transient analysis confirms that the maximum power excursion is less than 0.3 dB for 10-dB add/drop. ( 2007 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]


    An optimum superconducting ultra-wideband bandpass filter at VHF band

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2010
    Wei Chen
    Abstract A highly selective superconducting ultra-wideband filter with a passband from 125 to 260 MHz is designed and demonstrated using a microstrip structure. The filter is designed according to a circuit model for an optimum short-circuited stub transmission-line filter and consists of 10 shunt short-circuited stubs separated by connecting lines. The short-circuited stubs are quarter-wavelength long, and the connecting lines are half-wavelength long. The filter is realized on two 3-inch YBCO/LaAlO3 substrates, which are connected by two bonding wires. The short-circuited stubs are grounded via two grounding pads that are attached to the box wall by a number of SiAl bonding wires. The measured results exhibit a selective filtering characteristic equivalent to a 19-pole Chebyshev filter and a low insertion loss of less than 0.1 dB at center frequency without tuning. Furthermore, the experimental results of the filter are in good agreement with the simulated ones. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2639,2641, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25571 [source]


    Compact ultra-wideband bandpass filter using defected ground structures

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2010
    J. K. Lee
    Abstract In this letter, a compact ultra-wideband (UWB) bandpass filter (BPF) is presented with improved upper stopband performance using six defected ground structures (DGS). The proposed BPF is composed of seven DGSs which are positioned under the input and output microstrip line and coupled double step impedance resonator (CDSIR). By using CDSIR and open loop defected ground structure (OLDGS), we can achieve UWB BPF characteristics, and by using the conventional DGSs under input and output microstrip line, we can improve upper stopband performance. Simulated and measured results are found in good agreement with each other, showing a wide passband from 3.4 to 10.9 GHz, minimum insertion loss of 0.61 dB at 7.02 GHz and the group delay variation is less than 0.4 ns in the operating band while wide upper stopband with more than 30 dB attenuation up to 20 GHz. In addition, the proposed UWB BPF has a compact size. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2173,2175, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25436 [source]


    An ultra-wide stopband microstrip bandpass filter

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2010
    Guangming Zheng
    Abstract This article 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 ansoft designer v3 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. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2218,2221, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.25426 [source]


    Low power dual transformer injection locked frequency divider using 0.5 ,m GaAs E/D-mode PHEMTs process

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2010
    Po-Yu Ke
    Abstract This letter proposes a new divide-by-2 injection locked frequency divider (ILFD) fabricated by 0.5 ,m GaAs ED-Mode PHEMTs process and describes the operation principle of the dual-transformer ILFD. The first transformer is applied to replace two inductors of the cross-couple LC-tank oscillator circuit. The injection signal of the ILFD transmits into a transistor through a second transformer, which consisted of a bandpass filter achieving a high injection signal power and wide locking range. The measurement results show that the divider's free-running frequency were from 6.47 to 9.54 GHz (32.2%) with 3 V supply voltage. With an incident power of 0 dBm, the locking range is 3.07 GHz from the incident frequency 16.41 to 19.45 GHz (15.6%). The measured phase noise of free running VCO is ,92.2 dBc/Hz at 1 MHz offset frequency at 9.45 GHz and this value of the locked ILFD is ,128.4 dBc/Hz, which is 36.2 dB lower than the free running VCO. The core power consumption was 42 mW. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2302,2306, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25442 [source]


    High-performance UWB filter with a controllable notched band

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2010
    Chun-Ping Chen
    Abstract This article presents a design of a high-performance ultra-wideband (UWB) bandpass filter with a controllable notched band. Firstly, a UWB filter consisting of a stepped-impedance resonator (SIR) and two shunt short-circuited stubs is synthesized. Then, a narrow controllable notched band is introduced by a coupled external SIR. To be highlighted as an attractive advantage, as the characteristics of the UWB filter are not deteriorated by the placement of the external resonator, no further adjustments is needed for the synthesized UWB filter in this design. As an example, an (Federal Communications Commission) FCC UWB filter with a WLAN notch band is designed, simulated, and fabricated. A good agreement between the measured results and predicted ones validates the newly proposed design scheme and the filter prototype. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1842,1846, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25354 [source]


    C-shaped ultra-wideband bandpass filter with WLAN notch band

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2010
    Pai-Yi Hsiao
    Abstract A compact bandpass filter (BPF) embedded with 5.8 GHz wireless-LAN notch is presented for 3.1,10.6 GHz ultra-wideband (UWB) systems. The proposed UWB-BPF based on a defect-grounded structure is implemented with an FR4 board. Two open-loop resonators on the top layer provide a narrow notch band whose center frequency can be easily adjusted by varying the sizes of the open-loop. A simple C-shaped slot on the bottom ground layer is adopted to improve the bandwidth performance. The characteristics of UWB-BPF are analyzed and simulated using a circuit model of LC lump elements. The size of the filter is at least 34% less than those filters with the same specification. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1215,1218, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25153 [source]


    Dual-mode trapezium-loop microstrip bandpass filter

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2010
    You-Jun Zhang
    Abstract A novel compact and simple microstrip trapezium loop bandpass filter structure using only one resonator is developed in this letter, the inequilaterally structure perturbs the fields of the resonator and excite degenerate modes. Without coupling gaps, the new filter can reduce uncertainty in fabrication. Simulated results agree well with measured results. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:840,841, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25074 [source]


    Design and implementation of a high-performance V-band CMOS bandpass filter

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2010
    Jin-Fa Chang
    Abstract In this article, we demonstrate a low-insertion-loss V-band (50,75 GHz) bandpass filter with two finite transmission zeros by standard 0.13 ,m CMOS technology. The proposed filter architecture has the following feature: the low-frequency transmission-zero and the high-frequency transmission-zero can be tuned by the series-feedback capacitor Cs and the parallel-feedback capacitor Cp, respectively. Besides, low-insertion-loss is achieved by adopting thick microstrip-line (MSL) with optimized ground-plane pattern as the needed inductors to minimize the metal and substrate loss. This filter achieved insertion-loss (1/S21) lower than 3 dB over the frequency range of 52.2,76.7 GHz, input return loss (S11) better than ,10 dB over the frequency range of 50.2,80.6 GHz, and output return loss (S22) better than ,10 dB over the frequency range of 50.2,77.3 GHz. The minimum insertion-loss was 2.18 dB at 63.5 GHz, an excellent result for a V-band CMOS bandpass filter. The chip area was only 0.466 0.307 mm2, i.e., 0.143 mm2, excluding the test pads. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 309,316, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24935 [source]


    Novel microstrip bandpass filter based on defected ground structure and slotline coupling techniques

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2010
    Wenjie Feng
    Abstract A novel microstrip bandpass filter integrating the defected ground structure and slotline coupling technique is presented in this letter. A slotline resonator with a length of three-quarter wavelength at central frequency is etched on the ground, while a pair of radial stubs is centrally introduced. Two microstrip open stubs are then placed above the slotline resonator, saying, on the top plane of the dielectric substrate. By properly adjusting the lengths of the microstrip stubs, a wideband passband filter is thus implemented using coupling between 50-, microstrip (on the top plane) and the slotline (on the bottom). A prototype is fabricated to validate the proposed design strategies. The experiments and simulations both indicate good performances. The measured fractional bandwidth of prototype is about 89%, the return loss is less than ,15 dB in the whole passband. In addition, the measured rejection bandwidth at ,25 dB is even higher up to 10 GHz, thus, demonstrating a very good harmonic suppression ability. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 4,6, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24816 [source]


    Photonic microwave bandpass filter with negative coefficients based on flat-top

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2010
    Wang Jianping
    Abstract In this article, a novel microwave photonic filter with negative coefficient using semiconductor optical amplifiers and Fiber Bragg Gratings is proposed. Three major factors, including input current, grating coefficients and the input signal power are analyzed and compared respectively with scrutinize their affects to the filter response. Through the simulation, a better performance of the flat-top microwave photonic filter can be achieved. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 9,13, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24824 [source]


    A compact microstrip UWB BPF with nonuniformly short-circuited CPW resonator

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2010
    H. Chen
    Abstract A novel and compact ultra-wideband bandpass filter using hybrid microstrip/coplanar waveguide is presented. The proposed filter consists of a single coplanar waveguide with nonuniformly short-circuited resonator, which is broadside-coupled to two microstrip open-circuited stubs on the other side of a common substrate. The measured results show that the filter has a good performance, including a low insertion loss, a group delay variation of less than 0.25 ns within the passband, stop-band of up to 18.8 GHz at high frequencies, and an out-of-band rejection level of below ,16.5 dB from 11.4 to 18.8 GHz. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 216,218, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.24859 [source]


    Microstrip ring resonator bandpass filters using ceramic substrate

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2010
    Yuan-Bin Chen
    Abstract The miniaturization of ring bandpass filters by employing high-permittivity ceramic substrates (with respective dielectric constants of 9.7 and 23.5) are investigated. Microwave dielectric ceramics with high permittivity are commonly applied in several microwave communication components. With the advantages of compact size, high-permittivity ceramics can be used as the substrate for bandpass filters. Moreover, the fundamental characteristics of newly developed compact square-ring resonators have also been described and applied to the design of bandpass filters. In this paper, the designed square-ring resonators structures are simulated using an IE3D simulator. The responses of the fabricated bandpass filters using Al2O3 (,r = 9.7, tan , = 0.000036) and 0.875Mg0.95Zn0.05TiO3 -0.125Ca0.8Sm0.4/3TiO3 (,r = 23.5, tan , = 0.000021) ceramic substrates are designed at the center frequency of 2.4 GHz. This compact size, low loss bandpass filter should be useful in many wireless communication systems. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 218,220, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24847 [source]


    Compact dual-mode bandpass filter using arrow-shaped slot resonator

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2009
    Youngje Sung
    Abstract A novel design of a compact bandpass ring slot filter for achieving dual-mode operation is proposed and experimentally studied. By using an arrow-shaped slot structure as a resonator, the resonant frequency of the proposed filter is significantly lowered, which can lead to a large filter size reduction for a fixed frequency operation. Two degenerate modes are achieved by loading with proper asymmetry, which can be placed at the corner of diagonals. A prototype of the proposed design is implemented and measured. From the measured results, the proposed filter has about 5.2% bandwidth at the center frequency of 0.97 GHz and a minimum insertion loss of 1.07 dB within passband. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2989,2991, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24809 [source]


    Design of multilayer triangular substrate integrated waveguide filter in LTCC

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2009
    Wei Shen
    Abstract This article proposes a four-pole quasi-elliptic function triangular substrate integrated waveguide bandpass filter, which was fabricated using multilayer low-temperature cofired ceramic technology. In our design, neural network inverse model is adopted to fast capture the sizes of TSIW cavities, with the coupling matrix transformation implemented to achieve cross coupling on the basis of multilayer TSIW. A slot on the top metal layer is introduced so as to suppress the two higher spurious modes. The filter has 65% size reduction in comparison with its planar counterpart, with good agreement obtained between the simulated and measured S-parameters. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2582,2585, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24680 [source]


    An ultra-wideband bandpass filter using hybrid structure of microstrip and CPW

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2009
    Xun Luo
    Abstract An ultra-wideband (UWB) bandpass filter is proposed based on the hybrid structure of microstrip and coplanar waveguide (CPW). First, the detached-mode resonator is formed on the CPW layer, which composes a quarter-wavelength (,/4) multiple-mode resonator (MMR) with a short-stub and a ,/4 single-mode resonator. Then, two ,/4 microstrip open-stubs on the top side of the common substrate are introduced for bandwidth enhancement to meet the UWB passband limit. Quasi-elliptic function response and UWB operation are achieved. The simulated and measured results show an excellent agreement. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2470,2473, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24658 [source]


    Harmonic suppressed and size-reduced bandstop and bandpass filters

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2009
    Majeed A. S. Alkanhal
    Abstract New bandstop/bandpass microstrip structures with harmonic suppression are presented in this article. By replacing the series quarter-wavelength connecting lines of conventional open-stub bandpass/bandstop filters with the equivalent ,-shaped line section, compact open-stub bandstop/bandpass filters with second harmonic suppression are achieved. Transmission-line theory is used to derive the design equations of the equivalent ,-shaped lines. Simulation and experiments have also been done to validate the proposed design concept. When compared with the conventional open-stub Bandpass/Bandstop filters, the second harmonic is suppressed and size reduction is achieved in both the Bandstop/bandpass structures. Moreover, results confirm that the proposed shaped bandpass filter achieves a further third harmonic rejection. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2109,2114, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24580 [source]


    A novel compact ultrawideband (UWB) bandpass filter using multiple-mode resonator

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2009
    D. Chen
    Abstract In this letter, a novel compact ultrawideband (UWB) bandpasss filter (BPF) using the proposed multiple-mode resonator (MMR) is presented. The MMR is composed of a conventional microstrip hairpin resonator of which the two arms are connected by a section of microstrip line and a short-circuited point located in the middle of the hairpin resonator. Its first three resonant modes can be utilized to construct the UWB band. The tapped feeding structure has been used to realize desired tight couplings for designing the UWB BPF. The filter has been investigated numerically and experimentally. Both the simulated and measured results show that the filter has good performance, such as compact size, low-insertion loss, small group delay variation, and improved out-of-band performances. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1662,1664, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24424 [source]


    A wideband quasi-millimeter-wave bandpass filter using dual-mode resonator with 5/4 wavelength folded stubs

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2009
    Peng Cai
    Abstract A novel wideband quasi-millimeter-wave filter with good in-band and out-band performances is proposed in this article. A dual-mode square ring resonator loaded with two 5,0/4 (,0 is the center wavelength of the filter) folded stubs is introduced to realize a 3 dB passband bandwidth of about 15%. Because of the transmission zeros produced by the dual-mode ring resonator in the stopbands, the proposed filter exhibits sharp attenuations near the passband. On the other hand, a parallel-coupled two-mode resonator is introduced and integrated with the dual-mode ring resonator to get a further improvement of the out-band performance with wide stopbands. The fabricated filter has an insertion loss better than 2 dB in the passband and rejections greater than 20 dB at most of the frequencies in the stopbands. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1708,1711, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24457 [source]


    Resonant properties of the Sierpinski-based fractal resonator and its application on low-loss miniaturized dual-mode bandpass filter

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2009
    Chang-Sin Ye
    Abstract In this article, resonant characteristics of novel microstrip resonators based on the Sierpinski carpet fractal geometries are proposed in detail. With increasing the iteration order of the Sierpinski-based fractal resonators, the resonant frequency is decreased but the unloaded quality factor is slightly enhanced. The resonant properties are discussed using the RLC equivalent circuit. Additional, the design guide for bandpass filter using the nth order resonator is also developed. Using these fractal resonators, several dual-mode bandpass filters using different order resonators can be designed and fabricated to verify the advantages of the size and insertion loss reduction. It is also found good agreement between the simulation and measurement is achieved. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1358,1361, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24321 [source]


    Dual-mode dual-band bandpass filter based on double-sided parallel-strip line

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2009
    Xiu Yin Zhang
    Abstract This article presents a dual-mode dual-band bandpass filter based on double-sided parallel-strip line with an inserted conductor plane. Due to the isolation property of the conductor plane, this structure can provide two separate transmission paths to generate two passbands. No extra combination circuits are required at the input/output ports, simplifying the design and reducing circuit area. To demonstrate this idea, an experimental filter is implemented. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1361,1363, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24315 [source]


    Compact tri-band BPF design using spur-line-loaded tri-section SIRs

    MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2009
    Ching-Her Lee
    Abstract In this article, a new tri-band microstrip bandpass filter (BPF) is proposed. The BPF is composed of two folded, rectangular-shaped three-section SIRs (TSSIRs) whose first three resonant frequencies can be tuned to locate in the desired passbands. The BPF are 0 fed and the end sections of the TSSIRs are designed in an antiparallel fashion to produce zeros at appropriate frequencies for improving passband selectivity. In addition, by embedding spur lines and defected ground structures (DGS) in the BPF, extra transmission zeros around the first spurious passband are introduced to widen the upper stopband. The designed BPF is fabricated on an RT/Duroid 6010 substrate. The measured fractional bandwidths (minimum insertion losses) for the 1.57 GHz (GPS), 2.45 GHz (ISM), and 3.5 GHz (WiMAX) bands, respectively, are 11.5% (1 dB), 4.6% (2.19 dB), and 10.9% (1.3 dB), which agree well with those predicted by simulation. It also shows that for miniaturization purposes, the TSSIRs are made meandered to give an overall circuit size of only 23.29 10.94 mm2 for the designed BPF. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 989,991, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24208 [source]