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

  • microstrip Elliptic Function low pass filters using distributed elements or slotted ground structure
    IEEE Transactions on Microwave Theory and Techniques, 2006
    Co-Authors: Wenhua Tu, Kai Chang
    Abstract:

    This paper presents two microstrip Elliptic-Function low-pass filters, one using distributed elements and one using a slotted ground structure. The one using distributed elements consists of a microstrip line section in parallel with an interdigital capacitor; the other one using a slotted ground structure consists of a low-impedance microstrip line with a slotted ground structure cell under the center of the line. A transmission-line model and a full-wave simulation are used to calculate the inductance/capacitance values of the equivalent circuits. The design concept was validated through experiments showing good agreements with the full-wave simulated results

  • compact broad stopband Elliptic Function lowpass filters using microstrip stepped impedance hairpin resonators
    International Microwave Symposium, 2003
    Co-Authors: Lunghwa Hsieh, Kai Chang
    Abstract:

    A compact Elliptic-Function lowpass filter is developed. Multiple cascaded microstrip hairpin resonators operated at different 3-dB cutoff frequencies are used to design the filter. The filters are evaluated by experiment and simulation with good agreement. The return loss is better than 12.84 dB from DC to 0.81 GHz. The insertion loss is less than 0.5 dB. The rejection is greater than 35.7 dB from 1.5 to 10 GHz. This compact, low loss, sharp cutoff frequency response, and broad stopband lowpass filter should be useful in many wireless communication systems.

  • compact Elliptic Function low pass filters using microstrip stepped impedance hairpin resonators
    IEEE Transactions on Microwave Theory and Techniques, 2003
    Co-Authors: Lunghwa Hsieh, Kai Chang
    Abstract:

    A compact Elliptic-Function low-pass filter using microstrip stepped-impendance hairpin resonators and their equivalent-circuit models are developed. The prototype filters are synthesized from the equivalent-circuit model using available element-value tables. To optimize the performance of the filters, electromagnetic simulation is used to tune the dimensions of the prototype filters. The filter using multiple cascaded hairpin resonators provides a very sharp cutoff frequency response with low insertion loss. Furthermore, to increase the rejection-band bandwidth, additional attenuation poles are added in the filter. The filters are evaluated by experiment and simulation with good agreement. This simple equivalent-circuit model provides a useful method to design and understand this type of filters and other relative circuits.

  • dual mode quasi Elliptic Function bandpass filters using ring resonators with enhanced coupling tuning stubs
    IEEE Transactions on Microwave Theory and Techniques, 2002
    Co-Authors: Lunghwa Hsieh, Kai Chang
    Abstract:

    A novel microwave dual-mode quasi-Elliptic-Function bandpass filter structure has been designed and fabricated. The filter uses L-shaped coupling arms for enhanced coupling and dual-mode excitation. The effects of varying the length of tuning stubs and gap size between tuning stubs and ring resonator have been studied. Filters using multiple cascaded ring resonators with high rejection band are presented. The new filters have been verified by simulation and measurement with good agreement.

  • dual mode Elliptic Function bandpass filter using one single patch resonator without coupling gaps
    Electronics Letters, 2000
    Co-Authors: Lunghwa Hsieh, Kai Chang
    Abstract:

    A novel dual-mode, compact, and simple Elliptic-Function bandpass filter structure without coupling gaps is proposed. This filter has insertion loss 10 dB within 2.3-2.375 GHz. Without coupling gaps between the feed lines and the patch resonator, the new filter can provide a low insertion loss and reduce uncertainty in fabrication.

Zhenya Yan - One of the best experts on this subject based on the ideXlab platform.

  • the weierstrass Elliptic Function expansion method and its applications in nonlinear wave equations
    Chaos Solitons & Fractals, 2006
    Co-Authors: Yong Chen, Zhenya Yan
    Abstract:

    Abstract In this paper, based on the close relationship between the Weierstrass Elliptic Function ℘( ξ ;  g 2 ,  g 3 ) and nonlinear ordinary differential equation, a Weierstrass Elliptic Function expansion method is developed in terms of the Weierstrass Elliptic Function instead of many Jacobi Elliptic Functions . The mechanism is constructive and can be carried out in computer with the aid of computer algebra ( Maple ). Many important nonlinear wave equations arising from nonlinear science are chosen to illustrate this technique such as the new integrable Davey–Stewartson-type equation, the (2 + 1)-dimensional modified KdV equation, the generalized Hirota equation in 2 + 1 dimensions, the Generalized KdV equation, the (2 + 1)-dimensional modified Novikov–Veselov equations, (2 + 1)-dimensional generalized system of modified KdV equation, the coupled Klein–Gordon equation, and the (2 + 1)-dimensional generalization of coupled nonlinear Schrodinger equation. As a consequence, some new doubly periodic solutions are obtained in terms of the Weierstrass Elliptic Function. Moreover solitary wave solutions and singular solitary wave solutions are also given as simple limits of doubly periodic solutions. These solutions may be useful to explain some physical phenomena. The algorithm is also applied to other many nonlinear wave equations. Moreover we also present the general form of the method.

  • abundant families of jacobi Elliptic Function solutions of the 2 1 dimensional integrable davey stewartson type equation via a new method
    Chaos Solitons & Fractals, 2003
    Co-Authors: Zhenya Yan
    Abstract:

    Our extended Jacobi Elliptic Function expansion method is further improved to be a more powerful method, which is still called the extended Jacobi Elliptic Function expansion method, by using 12 Jacobi Elliptic Functions. The new (2+1)-dimensional integrable Davey–Stewartson-type is chosen to illustrate the approach. As a consequence, 24 families of Jacobi Elliptic Function solutions are obtained. When the modulus m→1, these doubly periodic solutions degenerate as soliton solutions. The method can be also applied to other nonlinear differential equations.

  • the new extended jacobian Elliptic Function expansion algorithm and its applications in nonlinear mathematical physics equations
    Computer Physics Communications, 2003
    Co-Authors: Zhenya Yan
    Abstract:

    More recently we have presented the extended Jacobian Elliptic Function expansion method and its algorithm to seek more types of doubly periodic solutions. Based on the idea of the method, by studying more relations among all twelve kinds of Jacobian Elliptic Functions. we further extend the method to be a more general method, which is still called the extended Jacobian Elliptic Function expansion method for convenience. The new method is more powerful to construct more new exact doubly periodic solutions of nonlinear equations. We choose the (2+1)-dimensional dispersive long-wave system to illustrate our algorithm. As a result, twenty-four families of new doubly periodic solutions are obtained. When the modulus m→1 or 0, these doubly periodic solutions degenerate as soliton solutions and trigonometric Function solutions. This algorithm can be also applied to other nonlinear equations.

  • jacobi Elliptic Function solutions of nonlinear wave equations via the new sinh gordon equation expansion method
    Journal of Physics A, 2003
    Co-Authors: Zhenya Yan
    Abstract:

    In this paper, based on the well-known sinh-Gordon equation, a new sinh-Gordon equation expansion method is developed. This method transforms the problem of solving nonlinear partial differential equations into the problem of solving the corresponding systems of algebraic equations. With the aid of symbolic computation, the procedure can be carried out by computer. Many nonlinear wave equations in mathematical physics are chosen to illustrate the method such as the KdV-mKdV equation, (2+1)-dimensional coupled Davey–Stewartson equation, the new integrable Davey–Stewartson-type equation, the modified Boussinesq equation, (2+1)-dimensional mKP equation and (2+1)-dimensional generalized KdV equation. As a consequence, many new doubly-periodic (Jacobian Elliptic Function) solutions are obtained. When the modulus m → 1 or 0, the corresponding solitary wave solutions and singly-periodic solutions are also found. This approach can also be applied to solve other nonlinear differential equations.

  • the extended jacobian Elliptic Function expansion method and its application in the generalized hirota satsuma coupled kdv system
    Chaos Solitons & Fractals, 2003
    Co-Authors: Zhenya Yan
    Abstract:

    Abstract In this paper an extended Jacobian Elliptic Function expansion method, which is a direct and more powerful method, is used to construct more new exact doubly periodic solutions of the generalized Hirota–Satsuma coupled KdV system by using symbolic computation. As a result, sixteen families of new doubly periodic solutions are obtained which shows that the method is more powerful. When the modulus of the Jacobian Elliptic Functions m →1 or 0, the corresponding six solitary wave solutions and six trigonometric Function (singly periodic) solutions are also found. The method is also applied to other higher-dimensional nonlinear evolution equations in mathematical physics.

T C Kofane - One of the best experts on this subject based on the ideXlab platform.

Lunghwa Hsieh - One of the best experts on this subject based on the ideXlab platform.

Jentsai Kuo - One of the best experts on this subject based on the ideXlab platform.

  • quasi Elliptic Function bandpass filter with upper stopband extension and high rejection level using cross coupled stepped impedance resonators
    Progress in Electromagnetics Research-pier, 2011
    Co-Authors: Jentsai Kuo, Shaochan Tang, Shuhsien Lin
    Abstract:

    Planar microstrip fllters are designed to have a quasi- Elliptic Function passband and extended upper stopband with a rejection level of 40 or 50dB. The design employs stepped-impedance resonators in a compact 2 £ 2 cross coupled conflguration. The geometric parameters of the resonators are planned to shift the third resonance as high as possible, and then the transmission zeros created by the structure are devised to suppress the second resonance, so that a wide upper stopband up to more than 4.5 times the passband frequency can be achieved. By employing the skew-symmetric input/output feeds, three transmission zeros in the frequency band of interest can be created. The leading two zeros are allocated on the both sides of the passband, generating a quasi-Elliptic Function response with enhanced roll-ofi rate in the transition bands, and the last zero incorporating with a zero created by anti-coupled-line at higher frequencies are employed to extend the rejection bandwidth. The measurement data agree very well with the simulation responses.

  • quadruple mode coupled ring resonator bandpass filter with quasi Elliptic Function passband
    IEEE Microwave and Wireless Components Letters, 2008
    Co-Authors: Uhou Lok, Yichyun Chiou, Jentsai Kuo
    Abstract:

    Quadruple-mode coupled-ring resonator is used to design quasi-Elliptic Function bandpass filters (BPFs) with a relatively wide bandwidth. The resonator consists of a pair of coupled rings with two open stubs symmetrically tapped to the inner ring. The stubs are used to move a transmission zero near the center frequency to lower transition band. It is believed that it is the first ring resonator BPF based on the coupled-ring to create four transmission poles and four transmission zeros. Two filters with relative bandwidths of 10% and 15% are fabricated and measured. Good agreement between simulation and measurement is obtained.

  • compact planar quasi Elliptic Function filter with inline stepped impedance resonators
    IEEE Transactions on Microwave Theory and Techniques, 2007
    Co-Authors: Jentsai Kuo, Chingluh Hsu, E Shih
    Abstract:

    Compact microstrip bandpass filters of orders N = 4,6, and 8 with quasi-Elliptic Function responses are synthesized with inline stepped-impedance resonators. The filters have enhanced transition responses since two transmission zeros are generated on both sides of the passband. Existence of these two zeros is investigated by formulating the Y-matrix of the equivalent circuit for the filter and taking adjacent and nonadjacent coupling into account. Some matrix elements Yj,j+2 representing coupling between two nonadjacent resonators are shown to have the opposite signs in both the lower and upper sides of the center frequency. This property leads to creation of the two transmission zeros on both sides of the passband. It is demonstrated that one more zero can be created in the rejection band by the tapped-line input/output scheme. Experimental circuits on substrates with epsivr = 2.2 and 10.2 are measured to validate the theory and design.

  • a microstrip Elliptic Function filter with compact miniaturized hairpin resonators
    IEEE Microwave and Guided Wave Letters, 2000
    Co-Authors: Jentsai Kuo, Mingjyh Maa
    Abstract:

    A four-pole Elliptic Function bandpass filter is designed using compact miniaturized microstrip hairpin resonators. It is shown that the filter occupies a very small area. The full-wave simulator IE3D is used to design the resonator and to calculate the coupling coefficients of the three basic coupling structures. Measurement results are compared with the computed responses.