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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 BinboğaIn 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 A broadband microwave amplifier design by means of immittance based data modelling tool(IEEE, 2002) Kılınç, Ali; Pınarbaşı, Hacı; Şengül, Metin; Yarman, Bekir Sıddık BinboğaIn this paper a practical broadband microwave amplifier design algorithm is introduced utilizing the immittance data-modelling tool. In the course of design, first, the optimum input and output terminations for the active device are produced employing the real frequency technique. Then, these terminations are modelled utilizing the new immittance-modelling tool to synthesize the front-end and back-end matching networks. An example is included to exhibit the implementation of the proposed design algorithm to construct a single stage BJT amplifier over a wide frequency band. It is expected that the proposed design algorithm will find applications to realize wideband microwave amplifiers put on MMIC for mobile communication.Yayın Mixed element wideband microwave amplifier design via simplified real frequency technique(IEEE Computer Society, 2014) Kılınç, Sedat; Köprü, Ramazan; Aksen, Ahmet; Yarman, Bekir Sıddık BinboğaIn this study, we illustrate the design and implementation of a wideband microwave small-signal amplifier composed of mixed elements. The design is based on Simplified Real Frequency Technique (SRFT). A design of low power amplifier circuit is completed and its simulations are performed in success. The circuit is designed with lumped elements, however, some of the lumped elements are converted to distributed elements for their convenience in production. In this way, a mixed element wideband microwave amplifier comprised of input/output matching networks with lumped and distributed elements has been formed. Layout work and also post layout simulation is given with satisfying results.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 BinboğaIn 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 Design and simulation of miniaturized communication systems employing symmetrical lossless two-ports constructed with two kinds of elements(IEEE, 2003) Yarman, Bekir Sıddık Binboğa; Aksen, Ahmet; Çimen, Ebru GürsuIn this paper, a semi-analytic method is presented to describe symmetrical lossless networks with two-kinds of elements, namely, distributed and lumped elements in cascade connection. in terms of the independently chosen parameters, element values of the lossless symmetrical networks are given by explicit formulas up to nine elements. It is expected that the results presented in this paper will find immediate usage in performance assessment, design and simulation of analog/digital wireless communication systems put on MMICs or VLSI chips.Yayın Unit element bandpass filter design via simplified real frequency technique for UWB microstrip patch antenna(IEEE Computer Society, 2014) Köprü, Ramazan; Kılınç, Sedat; Aksen, Ahmet; Yarman, Bekir Sıddık BinboğaDesign of a UWB (Ultra Wideband) microstrip patch antenna to operate in the first channel of the UWB standard and a bandpass (BP) UE (Unit Element) microstrip filter (BPUEF) for this antenna are studied and presented with promising experimental results. A typical UE BP filter is a lossless 2-port network which is formed with certain number of cascade connected commensurate transmission lines. Based on the simplified real frequency technique (SRFT) in Richards domain, driving point Darlington impedance function of the BPUEF is obtained via optimization such that optimum power transfer would be possible between a PA (power amplifier) and the antenna. Using the UE synthesis, characteristic impedance values of each UE is extracted from the input impedance function. Theoretical design (Matlab), simulation (ADS, Agilent Inc.) and the measurements are shown to be in a high degree of agreement.Yayın Multiband and concurrent matching network design via brune sections(IEEE, 2017) Yıldız, Serkan; Aksen, Ahmet; Yarman, Bekir Sıddık BinboğaA 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 BinboğaIn 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 BinboğaIn 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 A high precision Cascade Synthesis Technique for real frequency matching involving Brune and Darlington Type-C sections(IEEE, 2014) Yarman, Bekir Sıddık Binboğa; Aksen, Ahmet; Köprü, Ramazan; Aydın, Çağatay; Atilla, Doğu ÇağdaşIn this work, we introduce a high precision cascade synthesis technique for lossless matching networks involving Brune and Darlington Type-C sections. In the present manuscript, we generalized our previously introduced high precision LCladder synthesis algorithm to include the extraction of finite real frequency and right half plane (RHP) transmission zeros of an impedance function as Brune and Darlington Type-C sections respectively. In the modified synthesis algorithm, after each finite frequency and RHP transmission zero extraction, remaining immittance function is corrected using a parametric approach. It is shown that proposed high precision algorithm can synthesize immittance functions of up to 40 reactive elements with accumulated relative error in the order of 10(-1). The modified high precision synthesis package is developed in MatLab environment and it is integrated with the real frequency techniques to design high complexity matching networks over broad bands. An illustrative example is presented to exhibit the usage of the proposed high precision synthesis algorithm.
