Arama Sonuçları

Listeleniyor 1 - 5 / 5
  • Yayın
    Metamutator applications: a quadrature MOS only oscillator and transconductance/transimpedance amplifiers
    (Springer New York LLC, 2016-06-18) Göknar, İzzet Cem; Yıldız, Merih; Minaei, Shahram
    NMOS based circuit realizations of a sinusoidal quadrature oscillator, a transconductance, a transimpedance amplifier are presented. All the circuits are constructed with a voltage-mode “Metamutator” consisting of an analog adder and a subtractor which is one of its possible realizations. The most important feature of the proposed circuits is their extremely simple structures containing only twelve NMOS transistors (six for adder, six for subtractor). Another significant advantage of the proposed circuits is that no external passive element is needed for the oscillator and only one resistor is used for each amplifier circuit; a variable resistor can provide gain adjustability. The post-layout simulations of all the proposed circuits have been executed using TSMC 0.25 µm process parameters with ±1.25 V power supply voltage.
  • Yayın
    An accurate CMOS interface small capacitance variation sensing circuit for capacitive sensor applications
    (Springer Birkhauser, 2017-12) Momen, Hadi Ghasemzadeh; Yazgı, Metin; Köprü, Ramazan; Naderi Saatlo, Ali
    In this paper, an accurate front-end CMOS interface circuit for sensing very small capacitance changes in capacitive sensors is presented. The proposed structure scales capacitance variation to the sensible impedance changing. The scaling factor of the circuit can be easily tuned by adjusting bias points of the transistors. In order to cancel or decrease the parasitic components, the RC feedback and input transistor cascading techniques are employed in the design. To simulate the circuit, HSPICE simulator is utilized to verify the validity of the theoretical formulations in 0.18 mu m technology. According to schematic and post-layout simulation results, input impedance changes linearly versus capacitance variations up to 0.7 GHz, while the sensor capacitance changing is varied between 0 and 200 fF. According to the simulation results, total dc power consumption is obtained as low as 1 mW with 0.9 V power supply.
  • 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 Binboğa
    In 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
    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.
  • Yayın
    MOS only oscillator using adder and subtractor circuits
    (IEEE, 2015) Yıldız, Merih; Göknar, İzzet Cem; Minaei, Shahram
    In this paper an NMOS based sinusoidal oscillator is presented. The circuit is constructed with voltage-mode (VM) NMOS-based analog adder and subtractor circuits which respectively perform V-1+V-2 and V-1-V-2 operations on the input voltages. The most important feature of the proposed circuits is their extremely simple structures containing only twelve NMOS transistors (six for the adder, six for the subtractor). Another significant advantage of the proposed circuits is that no external passive components are being used. The post-layout simulations of the proposed oscillator circuit have been executed using TSMC 0.25 mu m process parameters with +/- 1.25 V power supply voltage.