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Yayın A tunable inductance topology to realize frequency tunable matching networks and amplifiers(IEEE, 2013) Atilla, Doğu Çağdaş; Aydın, Çağatay; Köprü, Ramazan; Nesimoğlu, Tayfun; Yarman, Bekir Sıddık BinboğaCoverage of commercial communication standards such as GSM, UMTS, Wi-Fi and Wi-Max within a single transceiver chip is one of the most desired properties by wireless communication manufacturers. In this regard, communication companies are keenly interested in the design of high power amplifiers for broadband cellular communications to achieve this coverage. In this work, design of broadband tunable matching networks is investigated using Real Frequency Techniques. In practical applications, tunability is needed to compensate for the load impedance variations with environmental effects. In order to be able to work on sample structures, impedance transforming filters with proper topology are chosen and a broadband tunable matching network with a tunability strategy is developed. Eventually a broadband amplifier has been designed using the tunable inductor concept.Yayın A method for low-pass filter designing by commensurate transmission lines(IEEE, 2016) Momen, Hadi Ghasemzadeh; Köprü, RamazanIt is well known that the complex Richards-Plane is a transformed domain of Laplace-Plane which is obtained under a tangent hyperbolic mapping. Network functions generated in terms of Richards's frequency are periodic in actual frequencies with periodicity of pi. Once a low-pass prototype network function is designed in Richards's domain, then its periodic feature makes the corresponding periodic band-pass network function to appear at the certain bands repetitively in the frequency axis. Depend on the application requirements, designer can choose the interested band among these repetitive bands. In this work, a filter is built with microstrip commensurate transmission lines in GSM operation pass-band (0.8 <= f <= 2.4 GHz) . This network can be used in communication applications which are designed to operate in the range of GHz as well as the application in a microstrip patch antenna. In the proposed design, Simplified Real Frequency Technique (SRFT) is employed in the frequency detection network, and the simulation result of microwave office tool (AWR) confirms the theoretical result obtained by MATLAB.Yayın A frequency transformation based real frequency design approach for dual-band matching(IEEE, 2017) Aksen, Ahmet; Yıldız, Serkan; Yarman, Bekir Sıddık BinboğaThis work describes a real frequency design approach for dual-band matching networks. The proposed design technique employs a direct low-pass to dual pass band frequency transformation in the scattering based real frequency design of transformer free double band matching filters. For prescribed matching pass-bands, the parameters of dual-band frequency transformation are also iterated to enhance the matching band control in the nonlinear optimization process. A dual band matching network design example is presented to illustrate the application of the design approach.Yayın İmge kodlaması için dalgacık paketlerinde küresel gösterim(IEEE, 2008-09-26) Ateş, Hasan Fehmi; Tamer, EnginBu bildiride, dalgacık dönüşümü için geliştirdiğimiz küresel kodlama algoritmasının dalgacık paketlerine uyarlanması sunulmuştur. Bu kodlayıcıda yerel katsayı enerjisi, dalgacık altbantlarında varolan uzamsal bilgiyi ayırt etmekte ve mevcut bit hızının bant içinde nasıl dağıtılacağına karar vermekte direk bir ölçüt olarak kullanılır. Yerel enerji daha yüsek çözünürlükte yani daha küçük boyutlu pencerelerde tanımlandıkça, kodlayıcı, bit hızını nasıl harcayacağı hakkındaki kararlarını otomatik olarak günceller. Bir sıradüzensel değişkenler kümesi kullanılarak yerel enerjinin en yüksek çözünürlüğe kadar yani dalgacık katsayılarının bireysel enerjilerine kadar belirlenmesi ve kodlanması mümkün olmaktadır. Enerji dağılımı açısından en iyi dalgacık paketinin kullanılması, algoritmanın kodlama performansı artırmaktadır. Sonuçta, özellikle dokulu imgeler için 1 dB’nin üzerinde kodlama kazancı elde edilmiştir.
