Arama Sonuçları

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  • Yayın
    Distributed wideband power amplifier using reactive coupled line feedback structure
    (Institute of Electrical and Electronics Engineers Inc, 2015) Amin, Hamid Yadegar; Özoğuz, Serdar; Köprü, Ramazan; Yarman, Bekir Sıddık Binboğa
    A wideband and flat gain distributed power amplifier using a GaN high electron mobility (HEMT) transistor has been designed. The frequency range covers 700 MHz to 4.5 GHz. The small signal gain has the average value of 10 dB. A reactive distributed shunt feedback structure is introduced and implemented by means of microstrip coupled lines. Also, fully distributed input and output impedance matching networks are implemented. The design and simulations are accomplished by advanced design system tool (ADS). The design has undergone large signal, small signal and electromagnetic analysis (EM-simulation). At VDS = 28 V and IDS = 340 mA. Down to the output power back-off of 5 dB at 4.5 GHz, power performance obtained with PAE higher than 35% where the maximum output power is 40.4 dBm.
  • 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 Binboğa
    In 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.