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
    Immitance data modelling via linear interpolation techniques: a classical circuit theory approach
    (Wiley-Blackwell, 2004-11) Yarman, Bekir Sıddık Binboğa; Kılınç, Ali; Aksen, Ahmet
    With the advancement of the manufacturing technologies to produce new generation analog/digital communication systems, immitance data modelling has gained renewed importance in the literature. Specifically, models are utilized for behaviour characterization, simulation of physical devices or to design sub-systems with active and passive solid-state devices. Therefore, in this paper, new computer aided tools are presented to model one port immitance data by means of linear interpolation techniques. The basic philosophy of the new modelling tools is based on the numerical decomposition of the immitance data into its minimum and Foster parts. Computer algorithms are presented to model the minimum and the Foster parts of the given immitance data. Implementations of these algorithms are exhibited by means of examples. Depending on the application, modelling tools based on linear interpolation techniques may present 'computational and practical' advantages over the existing interpolation techniques, non-linear curve fittings or regression methods. It is expected that the new modelling tools will be utilized to provide initial circuit topologies to the commercially available analysis/simulation and design packages.
  • Yayın
    A real frequency approach to describe lossless two-ports formed with mixed lumped and distributed elements
    (Urban & Fischer Verlag, 2001) Aksen, Ahmet; Yarman, Bekir Sıddık Binboğa
    The design of microwave filters, matching networks, amplifiers, that Is the "Broadband Networks" with mixed lossless lumped and distributed elements, has been a significant concern of the circuit theoreticians of the field. Yet, there has been no complete practical solution Introduced In the literature so far. In this paper, an attempt has been made to design broadband networks constructed with a cascade connection of low pass LC ladders connected with commensurate transmission lines. The new design procedure Is based on the two-variable description of the Simplified Real Frequency Technique. Up to five mixed-elements explicit equations are given to describe some selected network topologies. In general, synthesis Is carried out employing a decomposition technique first Introduced by Alfred Fettwels. A "Double Matching Design" example is presented to exhibit the merits and the application of the new approach.
  • Yayın
    Multiband filter design using generalized mapping functions and synthesis with lumped resonators
    (Czech Technical University, 2020-06-01) Yıldız, Serkan; Aksen, Ahmet; Kılınç, Sedat; Yarman, Bekir Sıddık Binboğa
    In this paper, a new multiband frequency mapping function is proposed to design multiband filter. The presented mapping function is a generalized form of the sequential low pass to band pass (LPtoBP) transformation. The multiband filter design is based on the application of the frequency mapping function on a LP prototype. The synthesis of the resulting multiband filter is obtained by lumped element resonators. Several examples are presented to validate the proposed design approach. A triple band filter implementation and measurement results are presented.
  • Yayın
    Microwave engineering expertise in Turkey
    (Institute of Electrical and Electronics Engineers Inc., 2018-05) Yarman, Bekir Sıddık Binboğa; Palamutçuoğulları, Osman; Kaya, İlker; Kızılbey, Oǧuzhan; Aksen, Ahmet; Akın, Tayfun; Özkan, Z. Levent; Oksar, İrfan; Nesimoğlu, Tayfun
    Reports on the status of microwave education and technological development in Turkey.
  • 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
    An immitance based tool for modelling passive one-port devices by means of darlington equivalents
    (Urban & Fischer Verlag, 2001) Yarman, Bekir Sıddık Binboğa; Aksen, Ahmet; Kılınç, Ali
    An immitance-based method is presented to model measured or computed data, obtained from a "passive one-port physical device" by means of its Darlington equivalent. In other words, the given data is modelled as a lossless two port terminated in a unit resistor. The basis of the new modelling tool rests on the numerical decomposition of the given immitance data into its Foster and minimum parts. Therefore, the proposed technique does not require any choice for the circuit topology to build the model. Rather, the optimum circuit topology that characterises the given data is the natural consequence of the modelling process proposed in this paper. A main algorithm is presented to construct the model from the given data. It is expected that the proposed modelling tool will find practical applications in the behaviour characterisation, simulation, and design of high speed/high frequency analog/digital mobile communication sub-systems manufactured on VLSI chips. An antenna-modelling example is included to systematically exhibit the implementation of the modelling technique.
  • 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.