فهرس المقالات Settling time

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  1 - Δ∑ Fractional-N Synthesizer for GSM-E-900 Frequency Standard
  Alireza Bagherzadeh Mostafa Yargholi
  This paper presents an integrated phase-locked loop (PLL) frequency synthesizer for wireless communication application in standard 0.18 µm CMOS process. Delta sigma modulator used for reducing phase noise. The use of  modulation concepts results in a beneficial noise sh أکثر

  This paper presents an integrated phase-locked loop (PLL) frequency synthesizer for wireless communication application in standard 0.18 µm CMOS process. Delta sigma modulator used for reducing phase noise. The use of  modulation concepts results in a beneficial noise shaping of the phase noise (jitter) introduced by fractional-N division. The this technique has the potential to provide low phase noise, fast settling time, and reduced impact of spurious frequencies when compared with existing fractionalPLL techniques. Simulation results show that the phase noise of frequency synthesizer is -108 @1MHz offset, and the PLL synthesizer provides output frequencies 880-915 MHz in uplink and 925-960 MHz in downlink. Fref is 26 MHz and channel spicing is 700 KHz. Moreover, benefiting from the combination of current-mode-logic (CML) the PLL consumes a total power dissipation of only 24.35 mW with a single 1.8 V supply including all the buffers. Although prescaler increases settling time (ts), it decreases power consumptions. Settling time in uplink is 425 ns and in downlink about 475 ns. تفاصيل المقالة
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  2 - Improvement of Left Ventricular Assist Device (LVAD) in Artificial Heart Using Particle Swarm Optimization
  Majid Neshat Yazdi Reihaneh Kardehi Moghaddam
  In this approach, the Left ventricular assist pump for patients with left ventricular failure isused. The failure of the left ventricle is the most common heart disease during these days. Inthis article, a State feedback controller method is used to optimize the efficie أکثر

  In this approach, the Left ventricular assist pump for patients with left ventricular failure isused. The failure of the left ventricle is the most common heart disease during these days. Inthis article, a State feedback controller method is used to optimize the efficiency of a samplingpump current. Particle Swarm Algorithm, which is a set of rules to update the position andvelocity, is applied to find the optimal State feedback controller parameters for the first time.In comparison to other optimization algorithms, including genetic algorithm, PSO has higherconvergence speed. As it is shown in the simulation part in the same number of iterations, thePSO algorithm decreases the cost function, which leads to desired transient and stabilityresponse of the system more effectively. In addition, in this work we propose a new structurefor the cost function which includes the dynamical equations of current sampling pump incombination with penalty sentences which decrease the speed and output fluctuations. In thisarticle, the system model and the system controlling parameters are set in such a way that theproposed cost function can be optimized. The efficiency of the method is illustrated insimulation part. تفاصيل المقالة