Arama Sonuçları

Listeleniyor 1 - 5 / 5
  • Yayın
    CMOS high-performance UWB active inductor circuit
    (Institute of Electrical and Electronics Engineers Inc, 2016) Momen, Hadi Ghasemzadeh; Yazgı, Metin; Köprü, Ramazan; Saatlo, Ali Naderi
    In order to maximize efficiency of the designed gyrator-based active inductor, advanced circuit techniques are used. Loss and noise are most important features of the AIs, where they should be low enough to have high-performance device. The gyrator-C topology is used to design a new low-loss and low-noise active inductor. The gyrator-C topology is potentially high-Q and all transistors are utilized in common-source configuration to have high impedance in input-output nodes. All transistors are free of body effect. The p-type differential pair input transistors and the feed forward path are employed to decrease noise of the proposed circuit. Additionally, inductance value and quality factor are adjusted by variation bias current which gives to the device tunable capability. HSPICE simulation results are presented to verify the performance of the circuit, where the 180 nm CMOS process and 1.8 V power supply are used. The noise voltage and power dissipation are less than 2.8 nV/ ? Hz and 1.3 mW, respectively.
  • Yayın
    Inductor saturation compensation in three-phase three-wire voltage-source converters via inverse system dynamics
    (Institute of Electrical and Electronics Engineers Inc., 2022-05-01) Özkan, Ziya; Hava, Ahmet Masum
    In three-phase three-wire (3P3W) voltage-source converter (VSC) systems, utilization of filter inductors with deep saturation characteristics is often advantageous due to the improved size, cost, and efficiency. However, with the use of conventional synchronous frame current control methods, the inductor saturation results in significant dynamic performance loss and poor steady-state current waveform quality. This article proposes an inverse dynamic model-based compensation (IDMBC) method to overcome these performance issues. For this purpose, two-phase exact modeling of the 3P3W VSC control system is obtained. Based on the modeling, the inverse system dynamic model of the nonlinear system is obtained and employed such that the nonlinear plant is converted to a virtual linear inductor system for linear current regulators to perform satisfactorily. Further, to control phase currents in the synchronous frame, a two-phase coordinate transformation is proposed. The IDMBC method is tested via dynamic command response and waveform quality simulations and experiments that employ saturable inductors reaching down from full inductance at zero current to 1/9th inductance at full current. The results obtained demonstrate the suitability of the method for 3P3W VSCs employing saturable inductors.
  • Yayın
    Designing a new high Q fully CMOS tunable floating active inductor based on modified tunable grounded active inductor
    (Institute of Electrical and Electronics Engineers Inc, 2015) Momen, Hadi Ghasemzadeh; Yazgı, Metin; Köprü, Ramazan
    A new Tunable Floating Active Inductor (TFAI) based on modified Tunable Grounded Active Inductor (TGAI) is proposed. Multi regulated cascade stage is used in TGAI to boost gain of input impedance and inductor value thus the Q factor enhancement obtained. The arrangement of Multi-Regulated Cascade (MRC) stage is caused the input transistor which determines AI self-resonance frequency to be as small as possible and it is free of body effect which is crucial in sub-micron technology. Compared to traditional CMOS spiral inductors, the active inductor proposed in this paper can substantially improve its equivalent inductance and quality factor. This TFAI was designed using the AMS 0.18 um RF CMOS process, which demonstrates an adjustable quality factor of 10?567 with a 6?284 nH inductance. The Q factor and value of active inductor is adjusted with bias current and flexible capacitance (varactor), respectively. The self-resonance frequency for both grounded and floating AI is about 6.2 GHz. The proposed active inductor also shows wide dynamic range and higher quality factor compared to conventional floating active inductor circuits.
  • Yayın
    Circuit model for given reflectance data constructed with mixed lumped and distributed elements for high speed/high frequency communication systems
    (IEEE, 2005) Yarman, Bekir Sıddık Binboğa; Şengül, Metin; Kılınç, Ali; Aksen, Ahmet
    In this paper, a reflectance-based "non linear interpolation method" is presented to model the measured or computed data, obtained from a "passive one-port physical device" using mixed lumped and distributed elements. Mixed element model is constructed with cascade connection of series inductors [L], commensurate transmission lines or so called Unit Elements [UE] and shunt capacitors[C]. Basis of the new model rests on the numerical generation of the scattering parameters of the lossless two-port constructed with cascade connection of simple [L]-[UE]-[C] elements which describes a lossless 2-port in Darlington sense. The new modeling technique does not require direct optimization of the circuit elements of the selected topology. Rather, two-variable reflection coefficient is directly determined by means of a non linear but "convergence guaranteed" interpolation process to best fit the given data. A low-pass filter input reflection coefficient modeling example is included to exhibit the utilization of the proposed modeling method.
  • Yayın
    Low-loss active inductor with independently adjustable self-resonance frequency and quality factor parameters
    (Elsevier Science BV, 2017-06) Köprü, Ramazan; Momen, Hadi Ghasemzadeh; Yazgı, Metin; Saatlo, Ali Naderi
    This work presents a new low-loss active inductor whose self-resonance frequency and quality factor parameters can be adjusted independently from each other. In order to achieve this property, a new input topology has been employed which consists of cascode structure with a diode connected transistor. Furthermore, the proposed input topology makes the device robust in terms of its performance over variation in process, voltage and temperature. Additionally, RC feedback is used to cancel series-loss resistance of the active inductor, which allows self-resonant enhancement as well. Schematic and post-layout simulation results show the theoretical validity of the design. To validate the design feasibility for process, voltage and temperature changes, Monte Carlo and temperature analysis are done. Suggested structure shows inductor behavior in the frequency range of 0.3–11.3 GHz. Maximum quality factor is obtained as high as 2.1k at 5.9 GHz. Total power consumption is as low as 1 mW with 1.8 V power supply.