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Chi-yang Chang - One of the best experts on this subject based on the ideXlab platform.

  • A switchable tunable dual-Band Filter using varator diodes for tuning and switching
    2017 IEEE CPMT Symposium Japan (ICSJ), 2017
    Co-Authors: Po-jung Chou, Chi-yang Chang
    Abstract:

    A switchable tunable dual-Band Filter using varator diodes for Band switching and frequency tuning is proposed. The tuning range of first Band is from 2.3 to 2.8 GHz and second one is from 1.8 to 2.1 GHz. The proposed dual-Band Filter is composed of two second-order Chebyshev short-ended hairpin comb Filters which embedded a pair of the varators as a switching and tuning elements. The simulated and measured results are matched well.

  • Tri-Band and quad-Band Filter design using E-shaped resonators
    2011
    Co-Authors: Yi-ting Kuo, Shi-yu Cheng, Chi-yang Chang
    Abstract:

    The semi-analytic procedure is provided for tri-Band and quad-Band Filter design based on E-shaped resonators. With analytic synthesized procedure in dual-Band Filter design and connect two Filters using double-diplexing configuration, the tri-Band and quad-Band performances can be achieved. The simulated results for the synthesized Filters agree well with the ideal performances after some fine tuning. Two microstrip implementations are provided to demonstrate the reliability of tri-Band and quad-Band Filter design.

  • analytical design of microstrip short circuit terminated stepped impedance resonator dual Band Filters
    IEEE Transactions on Microwave Theory and Techniques, 2011
    Co-Authors: Weishin Chang, Chi-yang Chang
    Abstract:

    This paper proposes an analytical method to design a dual-Band Alter using the short-circuit terminated half-wavelength stepped-impedance resonator (SIR). The SIR has an advantage to easily control the first and second resonances by adjusting its structural parameters. In the proposed method, the structural parameters of the SIR are obtained analytically according to the two passBand center frequencies and Bandwidths of the Filter. As a result, the achievable specifications of the dual-Band Filter can be rapidly determined. The coupling between adjacent SIRs is realized by a short-circuited stub, which is characterized as a K-inverter network. The dual-frequency transformer incorporated with the tapped-line input/output structure is used for the external coupling. Applying the analytical equations in the design process, a dual-Band Filter can be easily and quickly realized. More importantly, compared to the published dual-Band Filters, the proposed method is easier to design, especially for a relatively high-order dual-Band Filter. Two fourth-order and one sixth-order dual-Band Filters are designed and fabricated to demonstrate the proposed method.

Chang-hong Liang - One of the best experts on this subject based on the ideXlab platform.

  • a compact hexagonal dual Band substrate integrated waveguide Filter based on extracted pole technique
    Microwave and Optical Technology Letters, 2011
    Co-Authors: Jia Chen, Bian Wu, Liwei Jiang, Chang-hong Liang
    Abstract:

    In this article, a novel hexagon substrate integrated waveguide (SIW) dual-Band Filter is presented.First, the formula for calculating the resonant frequency of the dominant mode in triangle SIW cavity is given, then the triangle SIW cavity is used to construct a novel hexagon Filter, which reduces the size effectively. According to the extracted-pole technique using a parallel resonant circuit at the input and output resonator, a dual-Band Filter with two passBands at 9.6–9.85 and 10.15–10.4 GHz has been designed and fabricated. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:562–565, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25799

  • design of tri Band Filter based on stub loaded resonator and dgs resonator
    IEEE Microwave and Wireless Components Letters, 2010
    Co-Authors: Chang-hong Liang, Hao Di, Bian Wu
    Abstract:

    A tri-Band Bandpass Filter using stub loaded resonator (SLR) and defected ground structure (DGS) resonator is proposed in this letter. The DGS resonator on the lower plane constructs the first pass-Band, and the SLR on the upper plane forms the second and third pass-Bands, in which a DGS loop is properly used to provide the coupling between the SLRs. The three pass-Bands are combined together with a common T-shaped feed line, and a reasonable tuning method is adopted to tune the three pass-Bands with smooth responses. A compact tri-Band Filter with three pass-Bands centered at 2.45, 3.5, and 5.25 GHz is designed and fabricated. The measurement results agree well with the full-wave electromagnetic designed responses.

  • Design of Tri-Band Filter Based on Stub
    2010
    Co-Authors: Xin Lai, Chang-hong Liang
    Abstract:

    Atri-BandBandpassFilterusingstubloadedresonator (SLR) and defected ground structure (DGS) resonator is proposed in this letter. The DGS resonator on the lower plane constructs the first pass-Band, and the SLR on the upper plane forms the second and third pass-Bands, in which a DGS loop is properly used to pro- videthecouplingbetweentheSLRs.Thethreepass-Bandsarecom- bined together with a common T-shaped feed line, and a reason- able tuning method is adopted to tune the three pass-Bands with smooth responses. A compact tri-Band Filter with three pass-Bands centered at 2.45, 3.5, and 5.25 GHz is designed and fabricated. The measurement results agree well with the full-wave electromagnetic designed responses. Index Terms—Defected ground structure (DGS) resonator, stub- loaded resonator (SLR), tri-Band Filter, T-shaped feed line.

  • novel dual Band Filter incorporating defected sir and microstrip sir
    IEEE Microwave and Wireless Components Letters, 2008
    Co-Authors: Chang-hong Liang, Peiyuan Qin
    Abstract:

    This letter presents a novel approach to design dual-Band Bandpass Filter by using defected stepped impedance resonator (DSIR) and microstrip stepped impedance resonator (MSIR). A pair of MSIRs on the upper plane forms a cross coupled Filtering passage, and a pair of DSIRs at the lower plane constructs a linear phase Filtering passage. Both of them are fed by a common T-shaped microstrip feed line with source-load coupling. Then they are directly combined to construct a compact dual-Band Filter with two passBands centering at 2.35 GHz and 3.15 GHz, respectively. The measurement results agree well with the full-wave electromagnetic designed responses.

  • design of cross coupled dual Band Filter with equal length split ring resonators
    Progress in Electromagnetics Research-pier, 2007
    Co-Authors: Junwa Fan, Chang-hong Liang, Xiwang Dai
    Abstract:

    A compact dual-Band Bandpass Filter using equal-length split-ring resonators (SRRs) is proposed in this paper. The two- resonance frequency response of equal-length split-ring resonator is described in detail. A cross-coupled dual-Band Filter with four equal- length split-ring resonators is designed. Several finite out-of-Band attenuation poles are realized to improve the selectivity of the proposed Filter. The measurement of the Filter is in good agreement with the simulation.

Aurelio Campilho - One of the best experts on this subject based on the ideXlab platform.

  • optic disc segmentation using the sliding Band Filter
    Computers in Biology and Medicine, 2015
    Co-Authors: Behdad Dashtbozorg, Ana Maria Mendonca, Aurelio Campilho
    Abstract:

    Background: The optic disc (OD) centre and boundary are important landmarks in retinal images and are essential for automating the calculation of health biomarkers related with some prevalent systemic disorders, such as diabetes, hypertension, cerebrovascular and cardiovascular diseases. Methods: This paper presents an automatic approach for OD segmentation using a multiresolution sliding Band Filter (SBF). After the preprocessing phase, a low-resolution SBF is applied on a downsampled retinal image and the locations of maximal Filter response are used for focusing the analysis on a reduced region of interest (ROI). A high-resolution SBF is applied to obtain a set of pixels associated with the maximum response of the SBF, giving a coarse estimation of the OD boundary, which is regularized using a smoothing algorithm. Results: Our results are compared with manually extracted boundaries from public databases (ONHSD, MESSIDOR and INSPIRE-AVR datasets) outperforming recent approaches for OD segmentation. For the ONHSD, 44% of the results are classified as Excellent, while the remaining images are distributed between the Good (47%) and Fair (9%) categories. An average overlapping area of 83%, 89% and 85% is achieved for the images in ONHSD, MESSIDOR and INSPIR-AVR datasets, respectively, when comparing with the manually delineated OD regions. Discussion: The evaluation results on the images of three datasets demonstrate the better performance of the proposed method compared to recently published OD segmentation approaches and prove the independence of this method when from changes in image characteristics such as size, quality and camera field of view.

  • Cell Nuclei and Cytoplasm Joint Segmentation Using the Sliding Band Filter
    IEEE Transactions on Medical Imaging, 2010
    Co-Authors: Pedro Quelhas, Ana Maria Mendonca, Monica Marcuzzo, Aurelio Campilho
    Abstract:

    Microscopy cell image analysis is a fundamental tool for biological research. In particular, multivariate fluorescence microscopy is used to observe different aspects of cells in cultures. It is still common practice to perform analysis tasks by visual inspection of individual cells which is time consuming, exhausting and prone to induce subjective bias. This makes automatic cell image analysis essential for large scale, objective studies of cell cultures. Traditionally the task of automatic cell analysis is approached through the use of image segmentation methods for extraction of cells' locations and shapes. Image segmentation, although fundamental, is neither an easy task in computer vision nor is it robust to image quality changes. This makes image segmentation for cell detection semi-automated requiring frequent tuning of parameters. We introduce a new approach for cell detection and shape estimation in multivariate images based on the sliding Band Filter (SBF). This Filter's design makes it adequate to detect overall convex shapes and as such it performs well for cell detection. Furthermore, the parameters involved are intuitive as they are directly related to the expected cell size. Using the SBF Filter we detect cells' nucleus and cytoplasm location and shapes. Based on the assumption that each cell has the same approximate shape center in both nuclei and cytoplasm fluorescence channels, we guide cytoplasm shape estimation by the nuclear detections improving performance and reducing errors. Then we validate cell detection by gathering evidence from nuclei and cytoplasm channels. Additionally, we include overlap correction and shape regularization steps which further improve the estimated cell shapes. The approach is evaluated using two datasets with different types of data: a 20 images benchmark set of simulated cell culture images, containing 1000 simulated cells; a 16 images Drosophila melanogaster Kc167 dataset containing 1255 cells, stained for DNA and actin. Both image datasets present a difficult problem due to the high variability of cell shapes and frequent cluster overlap between cells. On the Drosophila dataset our approach achieved a precision/recall of 95%/69% and 82%/90% for nuclei and cytoplasm detection respectively and an overall accuracy of 76%.

Chunxia Zhou - One of the best experts on this subject based on the ideXlab platform.

  • tunable dual Band Filter based on stub capacitor loaded half mode substrate integrated waveguide
    IEEE Transactions on Microwave Theory and Techniques, 2017
    Co-Authors: Chunxia Zhou, Wen Wu
    Abstract:

    This paper presents an original and simple approach to the design of dual-Band Bandpass Filters (BPFs) using the proposed stub-capacitor-loaded half-mode substrate-integrated waveguide (HMSIW) structure. The stub-capacitor-loaded HMSIW structure is investigated and a set of analytical equations is provided for the determination of center frequency, transmission zero, coupling coefficient, and external quality factor. Dual-Band BPFs can be achieved by loading stub capacitor on the two sides of the HMSIW structure. The two passBands can be designed separately and controlled independently. To validate this method, a class of dual-Band Filters with a wide range of fractional Bandwidth ratios of the two passBands is designed. Finally, a dual-Band Filter, with each passBand tuned only by one control voltage, is fabricated and measured. The results show that the first passBand can be tuned in a frequency range from 1.85 to 2.67 GHz (36.4%) without any effect on the second passBand. In the meantime, the second passBand varies from 3.84 to 5.34 GHz (32.7%) without any effect on the first passBand. Good return loss is observed within a wide tuning range.

  • Design of Compact Dual-Band Filter in Multilayer LTCC with Cross Coupling
    Progress in Electromagnetics Research-pier, 2013
    Co-Authors: Chunxia Zhou, Yong-xin Guo, Lei Wang
    Abstract:

    A very compact low temperature co-fired ceramic (LTCC) dual-Band Filter is designed based on the proposed novel crosscoupling structure in this paper. A six-pole dual-Band Filter with four transmission zeros is synthesized using an analytical procedure. By incorporating the proposed novel cross-coupling structure and analyzing the coupling characteristic, the dual-Band Filter is realized with canonical topology in multilayer LTCC. It is demonstrated by the simulation and experiment that the proposed dual-Band Filter has both compact size and good selectivity.

  • A compact dual-Band Filter based on dual-mode resonators
    2011
    Co-Authors: Chunxia Zhou, Yong-xin Guo, Shaolin Yan
    Abstract:

    A dual-Band Filter has been designed and fabricated using two dual-mode resonators. Current distributions of four modes of this Filter are investigated using full-wave electromagnetic simulations. It shows that the folded canonical topology can be realized using the proposed dual-mode Filter structure. A dual-Band Filter is optimized using an analytical procedure and the corresponding coupling matrix with folded topology structure is synthesized. The designed topology exhibits a dual-Band response with center frequencies of 3.05 GHz and 3.21 GHz and in between isolation of 20 dB created by two in-Band transmission zeros. The designed dual-Band Filter shows insertion losses better than 3.4 dB for low-Band and 2.6 dB for high-Band, and narrow fractional Bandwidths of 2.24%.

Raafat R. Mansour - One of the best experts on this subject based on the ideXlab platform.

  • quasi elliptic waveguide dual Band Bandpass Filters
    IEEE Transactions on Microwave Theory and Techniques, 2019
    Co-Authors: Raafat R. Mansour, Ming Yu
    Abstract:

    This article presents a novel folded configuration of dual-Band Filter employing TE $_{11m}$ dual-mode elliptical cavity resonators. The proposed side-coupled configuration leads to a significant reduction of Filter footprint compared with previously reported in-line dual-Band Filter structures. Such configuration also facilitates cross couplings to realize advanced quasi-elliptic Filter functions. The structure employs irises for both sequential and cross couplings. The limitations of Bandwidth realization and spurious-free window are analyzed in detail, and new coupling structures are proposed to improve the overall in-Band and out-of-Band responses. All the proposed dual-Band designs have low insertion loss and allow for independent control of each frequency and coupling parameter. To demonstrate the concept, two 8-pole C-Band elliptical cavity dual-Band Filters are designed, manufactured, measured, and compared. To the best of the authors’ knowledge, this is the first reported folded dual-Band Filter configuration based on metallic waveguide cavities.

  • A Compact Waveguide Quasi-Elliptic Dual-Band Filter
    2019 IEEE MTT-S International Microwave Symposium (IMS), 2019
    Co-Authors: Li Zhu, Raafat R. Mansour
    Abstract:

    This paper presents a novel configuration of dual-Band Filter employing TE 11m dual-mode elliptical cavity resonators. The proposed side-coupled configuration leads to a significant reduction of Filter footprint compared to previously reported dual-Band Filter structures. Such configuration also facilitates cross-couplings to realize advanced quasi-elliptic Filter functions. To demonstrate the concept, an 8-pole C-Band elliptical cavity dual-Band Filter is designed, manufactured and measured.

  • Compact Waveguide Dual-Band Filters and Diplexers
    IEEE Transactions on Microwave Theory and Techniques, 2017
    Co-Authors: Li Zhu, Raafat R. Mansour
    Abstract:

    This paper presents a new class of dual-Band Filters and diplexers, realized based on dual-Band resonators. The proposed dual-Band Filter and diplexer do not require junctions and can achieve equivalent performance with fewer cavities, thus offering a significant reduction in size compared with traditional approaches. The concept is potentially applicable to most dual-Band cavities and is demonstrated in this paper using elliptical and rectangular waveguide cavities. The first design is an inline structure employing elliptical cavities, whereas the second design is implemented through a unique layout that combines the use of dual-Band and single-Band rectangular cavities. The result is a group of highly compact dual-Band Filters and diplexers that offer increased Q and an improved spurious-free window. To verify the concept, an eighth-order Ku-Band elliptical dual-Band Filter and a fourth-order Ku-Band rectangular diplexer are designed, manufactured, and tested to allow comparisons with traditional designs.