Arama Sonuçları

Listeleniyor 1 - 10 / 11
  • Yayın
    Design of a broadband microwave amplifier constructed with mixed lumped and distributed elements for mobile communication
    (IEEE, 2002) Yarman, Bekir Sıddık Binboğa; Çimen, Ebru Gürsu
    In this paper, we designed a broadband microwave amplifier utilizing. the "semi-analytic method to describe symmetrical lossless two-ports with two-kinds of elements", namely, distributed and lumped elements in cascade connection. It is expected that the results presented in this paper will find immediate application to design analog/digital mobile communication systems put on MMICs or VLSI chips.
  • Yayın
    Design and implementation of wideband microwave amplifiers based on Normalized Gain Function
    (Institute of Electrical and Electronics Engineers Inc., 2014) Köprü, Ramazan; Kılınç, Sedat; Aksen, Ahmet; Yarman, Bekir Sıddık Binboğa
    In this work, we introduce the design and implementation of wideband microwave amplifiers based on "Normalized Gain Function (NGF)" method. Normalized Gain Function is defined as the ratio of desired shape or frequency response of the gain function of the amplifier to be designed and shape of the transistor forward gain function. Synthesis of input/output matching networks (IMN/OMN) of the amplifier require target gain curves as the functions of normalized gain function to be tracked in two sequential nonlinear optimization processes. A prototype low power amplifier circuit is produced and measured to show the usability of the design approach.
  • Yayın
    Transformerless bandpass matching network design for Y-Shaped monopole antenna
    (IEEE, 2015) Aydın, Çağatay; Atilla, Doğu Çağdaş; Karakuş, Cahit; Köprü, Ramazan; Yarman, Bekir Sıddık Binboğa
    In this paper, a transformerless bandpass matching network design procedure is presented. The Real Frequency Techniques are powerful numerical methods to design wideband lossless 2-port networks such that filters and matching networks. In these techniques, the value of the termination resistance of the designed network could not be yielded as 50 ohm by numerical package. Hence, a transformer is also required for 50 ohm termination which is not practical for high frequency applications. Also in this study a novel wideband monopole antenna is presented. The proposed antenna is consisting of two major elements; Y-shaped impedance matching plate and hemi-circular radiator. Moreover Y-shaped impedance matching plate connected to a feeding probe excites the suspended hemi-circular radiator via air gap. and its frequency band is expanded by using transformerless bandpass design procedure.
  • Yayın
    Circuit model for given reflectance data constructed with mixed lumped and distributed elements for high speed/high frequency communication systems
    (IEEE, 2005) Yarman, Bekir Sıddık Binboğa; Şengül, Metin; Kılınç, Ali; Aksen, Ahmet
    In this paper, a reflectance-based "non linear interpolation method" is presented to model the measured or computed data, obtained from a "passive one-port physical device" using mixed lumped and distributed elements. Mixed element model is constructed with cascade connection of series inductors [L], commensurate transmission lines or so called Unit Elements [UE] and shunt capacitors[C]. Basis of the new model rests on the numerical generation of the scattering parameters of the lossless two-port constructed with cascade connection of simple [L]-[UE]-[C] elements which describes a lossless 2-port in Darlington sense. The new modeling technique does not require direct optimization of the circuit elements of the selected topology. Rather, two-variable reflection coefficient is directly determined by means of a non linear but "convergence guaranteed" interpolation process to best fit the given data. A low-pass filter input reflection coefficient modeling example is included to exhibit the utilization of the proposed modeling method.
  • Yayın
    Multiband matching network design via transformation based real frequency approach
    (IEEE, 2016) Yıldız, Serkan; Aksen, Ahmet; Yarman, Bekir Sıddık Binboğa
    In this paper, a new method is presented for multiband matching network design. Low pass to band pass (LP-BP) frequency transformation is incorporated with the parametric Real Frequency Technique (RFT) for creating multiband network functions. In the new parametric approach, the poles of a low pass type impedance function are optimized under LP-BP transformation, for multiband matching of complex terminations. The resultant matching network is realized with resonance sections yielding multiband transducer power gain (TPG) characteristic.
  • Yayın
    Multiband and concurrent matching network design via brune sections
    (IEEE, 2017) Yıldız, Serkan; Aksen, Ahmet; Yarman, Bekir Sıddık Binboğa
    A general multiband matching network design methodology for complex load impedance terminations is presented. In the proposed approach, Real Frequency Techniques (RFT) are used to define and optimize the multiband matching network. In the characterization of the multiband network, multiple notch bands are obtained by the employment of finite transmission zeros (FTZ) in the transfer function. Brune section realization of finite transmission zeros and the associated coupled coil free realizations are discussed. A triple band matching network design for a triple band Sierpinski antenna load is presented to illustrate the performance of the proposed approach.
  • Yayın
    A parametric approach to construct two-variable positive real impedance functions for the real frequency design of mixed lumped-distributed matching networks
    (IEEE, 2004) Aksen, Ahmet; Pınarbaşı, Hacı; Yarman, Bekir Sıddık Binboğa
    In this paper, a parametric approach to construct two-variable positive real driving point impedance functions characterizing lossless ladder networks with mixed lumped and distributed elements is presented. The proposed approach is based on the generation of two-variable positive real impedance functions from the single variable boundary conditions. Utilizing the proposed parametric construction algorithm, real frequency matching technique is extended to the design of matching networks with mixed lumped and distributed elements. The application of the approach is illustrated by a broadband microwave amplifier design incorporating mixed lumped and distributed type matching networks. The resultant design has been compared with the AWR Microwave Office software simulation.
  • Yayın
    Quad-band matching network design with real frequency technique employing frequency transformation
    (IEEE, 2017) Yıldız, Serkan; Aksen, Ahmet; Yarman, Bekir Sıddık Binboğa
    In this study, a piecewise frequency transformation is presented for quad-band (QB) matching network design. The real frequency direct computational technique RFDCT is incorporated with the generated QB transformation. The proposed approach employs three sequential application of low-pass (LP) to band pass (BP) transformation. Transformation parameters are derived by using a direct LP to QB mapping scheme. RFDCT is used to find the optimum element values of a pre-defined transformer free matching network topology within a nonlinear iteration routine which incorporates the QB transformation. For assigned quad pass-bands, the parameters of QB transformation are also optimized to improve transducer power gain (TPG) of the matching network. A quad-band matching network design example is given to illustrate application of the proposed method.
  • Yayın
    RFT Based multiband matching network design with foster resonance sections
    (IEEE, 2015) Yıldız, Serkan; Aksen, Ahmet; Yarman, Bekir Sıddık Binboğa
    A new method for a multi band matching network design is introduced in this paper. Foster resonance sections are used to create transmission zeros. This effect brings gain degradation at Transducer Power Gain (TPG) of the matching circuit at assigned frequencies of resonance sections. Single matching problem is concerned. It has been shown that proposed method gives good control on creating multiband characteristics.
  • Yayın
    A reflectance-based computer aided modelling tool for high speed/high frequency communication systems
    (IEEE, 2001) Yarman, Bekir Sıddık Binboğa; Aksen, Ahmet
    A reflectance-based method is presented to model the measured or computed data, obtained from a "passive one-port physical device" by means of its Darlington equivalent. The basis of the new modelling tool rests on the numerical generation of the scattering parameters of the Darlington 2-port from the given reflectance employing the losslessness condition. The proposed technique does not require any choice for the circuit topology to build the model. The circuit topology is the natural consequence of the modelling process.