Arama Sonuçları

Listeleniyor 1 - 8 / 8
  • Yayın
    Design of multiband matching ladders without mutual coupling using parametric representation of Brune functions
    (John Wiley and Sons Inc, 2020-10-01) Yıldız, Serkan; Aksen, Ahmet; Yarman, Bekir Sıddık Binboğa
    In this study, a semianalytical method for the design of mutual coupling free multiband matching networks is introduced. A new parametric representation of Brune functions is used for the construction of multiband ladder network topologies without mutual induction. The method involves the use of Fujisawa's constraints for low pass ladders having finite transmission zeros, in a parametric representation of driving point impedance function resulting in mutual inductance free Brune sections. The developed parametric representation is incorporated with Real Frequency Techniques to design matching networks with a plurality of pass bands. Several illustrative design examples are presented to validate the method.
  • Yayın
    Dual band matching network design via real frequency technique by mapping from a band pass prototype
    (IEEE, 2016) Yıldız, Serkan; Aksen, Ahmet; Yarman, Bekir Sıddık Binboğa
    In this study, a new method of design for dual band matching network is presented. A transformer-less Band Pass (BP) prototype matching network is synthesized with well-known Simplified Real Frequency Technique (SRFT) via cascaded combination of Low Pass (LP) and High Pass (HP) sections and optimized under LP to BP frequency transformation to create dual band response. Scattering parameters based descriptive functions of transformer-less BP prototype network is obtained. Dual band response is derived via frequency mapping on the produced BP prototype network. The new method combines several advantages both in design and realization step. The application of this method is discussed with sequential transformation based approach. A dual band matching network design for a PIFA antenna is presented. By using this method dual band characteristic is derived with only one step application of frequency mapping which let use to have more practical realizations.
  • 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
    Low pass filter design with improved stop-band suppression and synthesis with transformer-free ladders
    (John Wiley and Sons Inc, 2021-09) Yıldız, Serkan; Aksen, Ahmet; Kılınç, Sedat; Yarman, Bekir Sıddık Binboğa
    A new method to design transformer-free low pass (LP) ladder network with improved stop-band suppression performance is introduced. The parametric representation of back-end impedance of LP filter network is established with minimum impedance part and a Foster reactance part. The constructed impedance function is optimized by using real frequency technique. It has been shown that the proposed method provides LP filters which have superior stop-band suppression in comparison with classical transfer function-based filters with same complexity. The synthesis of the LP filter is obtained with the proposed element extraction procedure and resulted with fully realizable network elements in ladder form. An LP filter design and application by employing the proposed technique is provided. The measurement results of the prototyped filter are presented.
  • Yayın
    Transformer-less ladder network design with non-minimum impedance functions
    (Institute of Electrical and Electronics Engineers Inc., 2019-11) Yıldız, Serkan; Aksen, Ahmet; Yarman, Bekir Sıddık Binboğa
    In this study, a new method of design for transformer-less ladders is introduced. It has been shown that, given a non minimum impedance function which includes finite transmission zeros (FTZs) can be synthesized without transformers. The parametric form of non-minimum impedance function is constructed by cascading a dummy Foster part reactance and a minimum part impedances. The synthesis procedure starts with extraction of Foster part then the minimum part. Even the negative inductors are occurred while extracting FTZs as Brune sections it is shown that, all negative elements are eliminated by the positive valued inductors of adjacent Brune sections. If the impedance function has been only composed of a minimum part impedance then it will not possible to obtain this conclusion. Therefore the proposed parametrical construction provides transformer-free ladder network topologies. Real Frequency Technique is incorporated to optimize the realizable impedance over the band of interest. An low pass (LP) design example is presented.
  • Yayın
    Real frequency design of multiband matching networks with mixed lumped-distributed elements and foster resonance sections
    (IEEE, 2018) Yıldız, Serkan; Aksen, Ahmet; Yarman, Bekir Sıddık Binboğa
    In this study, a multiband matching network design technique is presented. Mixed lumped and distributed elements are used to form Transducer Power Gain (TPG) of the matching network. Finite frequency transmission zeros are included in final design to create multiband TPG characteristic. Foster resonance sections are used to realize finite transmission zeros. Approximate distributed model of Foster resonance section is incorporated in design. An illustrative dual band matching network design for a PIFA antenna is presented. It has been shown that using distributed equivalent models of Foster resonance sections in mixed matching network design provides satisfactory TPG levels at intended frequency bands.
  • Yayın
    Dual band filter design using real frequency technique and frequency transformation
    (Istanbul Univ, Fac Engineering, Elektrik-Elektronik Muhendisligi Bolumu, 2017) Yıldız, Serkan; Aksen, Ahmet; Yarman, Bekir Sıddık Binboğa
    In this work, we present a frequency transformation based dual-band filter design approach using scattering based real frequency technique. In the design process, conventional low-pass to band-pass frequency transformation is integrated with the simplified real frequency technique to construct double pass-band filters. The approach is particularly advantageous for designing matching filters between different termination resistances. As an alternative to a direct low-pass to dual-band frequency transformation, the use of dual-band mapping on a normalized band-pass prototype is investigated for efficient control of the passbands. Application of the proposed approaches for dual-band filters is presented by comparative design examples.
  • Yayın
    Dual band stop filter design via frequency transformation and synthesis with lumped resonators
    (Institution of Engineering and Technology, 2020-05-01) Yıldız, Serkan; Aksen, Ahmet; Kılınç, Sedat; Yarman, Bekir Sıddık Binboğa
    This study presents a new compact design technique for dual band stop (DBS) filter. Analytical formulation of DBS frequency transformation/mapping is derived in terms of parametric representation of band characteristic of DBS filter. The analytical derivation of the transformation function is based on sequential application of classical low pass to band stop (LP to BS) and low pass to band pass (LP to BP) transformations. Assigned band characteristic of DBS filter can be achieved by applying the proposed transformation function on an LP prototype network. The explicit network topologies for DBS reactance mapping are presented. Several numerical examples are provided to validate the proposed mapping function. An implantation example of DBS filter for GSM900 and GSM1800/UMTS bands is given. Mixed element realisation of the designed filter and measurement results of the design are presented.