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Yayın 2W wideband microwave PA design for 824-2170 MHz band using normalized gain function method(IEEE, 2013) Köprü, Ramazan; Kuntman, Hulusi Hakan; Yarman, Bekir Sıddık BinboğaIn this work, we present the design of a 2W linear wideband microwave PA (power amplifier) targeted to operate in 824-2170 MHz mobile frequency range covering GSM850, EGSM, DCS, PCS and WCDMA. The design is basically based on the NGF (Normalized Gain Function) method which is very recently introduced into the literature. NGF is defined as the ratio of T and |S-21|(2), i.e. T-NGF= T/|S-21|(2), shape of the gain function of the amplifier to be designed and the shape of the transistor forward gain function, respectively. Synthesis of input/output matching networks (IMN/OMN) of the amplifier requires target gain functions, which are mathematically generated in terms of TNGF. The particular transistor used in the design is FP31QF, a 2W HFET from TriQuint Semiconductor. Theoretical PA performance obtained in Matlab is shown to be in a very high agreement with the simulated performance in MWO (Microwave Office) of AWR Inc.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 On numerical design technique of wideband microwave amplifiers based on GaN small-signal device model(Springer, 2014-10) Köprü, Ramazan; Kuntman, Hulusi Hakan; Yarman, Bekir Sıddık BinboğaThis work presents an application of Normalized Gain Function (NGF) method to the design of linear wideband microwave amplifiers based on small-signal model of a device. NGF has been originally developed to be used together with an S-parameter (*.s2p) file, whereas this work enables the NGF to be able to work with explicit S-parameter formulae derived from the small-signal model of the device. This approach provides the designer to be able to use simple set of S-parameter equations instead of S-parameter file of the device. Representation of the device simply by several model equations not only eliminates the need of carrying large number of data but also provides the capability of equation-based easy, realistic and equispaced S-parameter data generation in any desired resolution in frequency axis without requiring interpolation. NGF is defined as the ratio of T and |S-21|(2), i.e. T-N = T/|S-21|(2), gain function of the amplifier to be designed and transistor forward gain function, respectively. Synthesis of output/input matching networks (OMN/IMN) of the amplifier requires two target gain functions in terms of T-N, to be used in two sequential non-linear optimization procedures, respectively. An amplifier with a flat gain of similar to 10 dB operating in 0.8-2.35 GHz is designed using a small-signal model of an experimental GaN-HEMT. Theoretical amplifier performance obtained in Matlab is shown to be in excellent agreement with the simulated performance in MWO (Microwave Office, AWR Inc.). A prototype low-power amplifier having a similar to 10 to 12 dB gain, operating in (0.9-1.5 GHz) is also produced and measured which yielded good performance results.Yayın A design technique of 50 Ω terminated bandpass matching network and its implementation to a Y-shaped monopole antenna matching(Springer, 2016-12) Aydın, Çağatay; Atilla, Doğu Çağdaş; Köprü, Ramazan; Kılınç, Sedat; Karakuş, Cahit; Yarman, Bekir Sıddık BinboğaIn this paper, a 50 Ω terminated or in other words transformerless bandpass matching network design methodology and an implementation example are presented. The real frequency techniques are powerful numerical methods to design wideband lossless two-port networks such as filters, matching networks and amplifiers. In these techniques, the value of the termination resistance of the designed network could not be yielded as 50 Ω by numerical package. Hence, a transformer is also required for 50 Ω termination which is not practical for high frequency applications. By employing the proposed procedure, it is guaranteed to obtain transformerless bandpass matching network. Also in this study a wideband suspended monopole antenna is examined. The proposed antenna consists 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. Consequently, a transformerless bandpass matching network is designed to filter and expand the operational frequency bandwidth of the proposed antenna. It has been observed that ideal circuit and the layout of the matching network simulation have good agreement.Yayın A novel method to design wideband power amplifier for wireless communication(IEEE, 2013) Köprü, Ramazan; Kuntman, Hulusi Hakan; Yarman, Bekir Sıddık BinboğaA new approach is presented to design microwave amplifiers to deliver maximum output power using Simplified Real Frequency Technique (SRFT). Proposed method tracks the maximum stable gain (MSG) curve of the active device (BJT, FET etc.) under consideration. Maximum Stable Gain Amplifier (MSGA) possesses higher gain than that of the constant or Flat Gain Amplifier (FGA) along the operating frequency band. Compared to FGA, it is this feature that makes MSGA high efficiency and low DC power consumption amplifier. Employing the proposed design method, a MSG power amplifier is constructed over the frequency band of 800-5200 MHz which can be utilized for GSM, UMTS, Wi-Fi and Wi-MAX applications.Yayın Wideband bandpass filter design for X band horn antenna via numerical techniques(IEEE Computer Society, 2015) Köprü, Ramazan; Aydın, Çağatay; Atilla, Doğu Çağdaş; Kılınç, Sedat; Yarman, Bekir Sıddık BinboğaDesign of an X band horn antenna and a wideband unit element microstrip bandpass filter (UEBPF) for this antenna are presented with satisfactory agreement between theoretical and simulation results. Numerical methods known as real frequency techniques (RFTs) have been utilized in Richards domain to yield optimum driving point Darlington input impedance function belonging to the UEBPF that enables a maximum RF power transmission between the designed horn antenna and an RF driving source. Using a high precision Richards immittance synthesis package in Matlab, characteristic impedance values of each UE, out of k number of commensurate (equal length) transmission lines forming the UEBPF, is extracted from the input impedance function. Theoretical design (Matlab of Mathworks Inc.) and simulation (ADS of Agilent Inc., HFSS of ANSYS Corp.) results are shown to be very promising and in a high degree of agreement with each other.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 Computer aided high precision Darlington synthesis for real frequency matching(Institute of Electrical and Electronics Engineers Inc, 2014) Yarman, Bekir Sıddık Binboğa; Aksen, Ahmet; Köprü, Ramazan; Aydın, Çağatay; Atilla, Doğu ÇağdaşIn this work, we introduce a high precision synthesis algorithm to include the extraction of finite frequency and right half plane (RHP) transmission zeros of an impedance function as Brune/Darlington Type-C sections. After each transmission zero extraction, remaining immittance function is corrected using a parametric approach. It is shown that proposed high precision synthesis algorithm can synthesize immittance functions up to 40 reactive elements with accumulated relative error in the order of 10-1. The high precision synthesis package is integrated with the real frequency techniques to design matching networks over broadbands. Examples are presented to exhibit the usage of the proposed high precision synthesis algorithm.Yayın Wideband matching network design for a V-Shaped square monopole antenna using Real Frequency Technique(IEEE, 2013) Köprü, Ramazan; Aydın, Çağatay; Atilla, Doğu Çağdaş; Karakuş, Cahit; Yarman, Bekir Sıddık BinboğaIn this paper, design and simulation of a wideband matching network for a broadband V-shaped square monopole antenna is presented. Matching network design is unavoidable in most cases even vital to facilitate a maximally flat power transfer gain for an antenna. In the work, the matching network design is done for a particular square monopole antenna with V-shaped coupling element that has essentially bandwidth increasing effect. The V-shaped antenna had been manufactured, tested and analyzed elaborately in a previous work. With this work, it is now equipped by a matching network. 'Real Frequency Technique' (RFT) is employed in matching network design.Yayın Novel approach to design ultra wideband microwave amplifiers: Normalized gain function method(Spolecnost Pro Radioelektronicke Inzenyrstvi, 2013-09) Köprü, Ramazan; Kuntman, Hulusi Hakan; Yarman, Bekir Sıddık BinboğaIn this work, we propose a novel approach called "Normalized Gain Function (NGF) method" to design low/medium power single stage ultra wide band microwave amplifiers based on linear S parameters of the active device. Normalized Gain Function T-NGF is defined as the ratio of T and vertical bar S-21 vertical bar(2), desired shape or frequency response of the gain function of the-amplifier to be designed and the shape of the transistor forward gain function, respectively. Synthesis of input/output matching networks (IMN/OMN) of the amplifier requires mathematically generated target gain functions to be tracked in two different nonlinear optimization processes. In this manner, NGF not only facilitates a mathematical base to share the amplifier gain function into such two distinct target gain functions, but also allows their precise computation in terms of T-NGF=T/vertical bar S-21 vertical bar(2) at the very beginning of the design. The particular ainplifier presented as the design example operates over 800-5200 MHz to target GSM, UNITS,. Wi-Fi and WiMAX applications. An SRFT (Simplified Real Frequency Technique) based design example supported by simulations in MWO (Micro Wave Office from AWR Corporation) is given using a 1400 mW pHEMT transistor, TGF2021-01 from TriQuint Semiconductor.
