فهرست مطالب

مجله مهندسی برق و الکترونیک ایران
سال چهاردهم شماره 4 (زمستان 1396)

  • تاریخ انتشار: 1396/10/27
  • تعداد عناوین: 13
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  • Amir Farzad Khavari, Khalil Mafinezhad, Mohammad Maymandi Nejad Pages 1-13
    A new approach for designing an ultra wideband (UWB) CMOS low noise amplifier (LNA) is presented. The aim of this design is to achieve a low noise figure, reasonable power gain and low power consumption in 3.1-10.6 GHz. Also, the figure of merit (FOM) is significantly improved at 180nm technology compared to the other state-of-the-art designs. Improved π-network and T-network are used to obtain a high and smooth power gain for the whole frequency band. Impedance matching and noise matching are designed with double feedback and only one inductor that are used at the input of the LNA. Post layout simulation is done for design validation. In this design post layout simulations show the low noise figure of 3.85±0.25 dB, reasonable power gain (18.08dB) and input return loss less than -9.1dB in full band of UWB. The power consumption of the circuit is only 11.3mW from 1.8V voltage supply. The LNA has the group delay about 111±43ps. An input third-order intermodulation point (IIP3) of -9.2 dBm is achieved at 4 GHz. The layout area is 1.056 × 0.658 mm2.
    Keywords: Ultra wideband, UWB, Low Noise Amplifier, LNA, CMOS.
  • Atefeh Gholipour, Khalil Mafinezhad Pages 15-21
    In the last decade Micromechanical components for communication applications has been fabricated via IC-compatible MEMS technologies. In fact, its most important impact is not at the component level, but rather at the system level, by offering alternative transceiver architectures that reduce power consumption and enhance performance. In this paper a mixer-filter for AM frequency receiver with MEMS based on one clamped-clamped beam resonator is presented. Mixing and filtering functions are achieved by one component. By combining mixer and filter in one component, in addition to size reduction for portable communication devices, power consumption is also reduced. Mixer-filter can down-convert the RF frequency of 1.655MHz to IF frequency of 455 kHz with a bandwidth of 8 kHz by local oscillator frequency of 2.11 MHz. This technique can be used for much higher RF frequencies. The unloaded Q of this device is 7714 and it could be used as narrow band filter, this design has high linearity too with IIP3 13.6dBm. Above all, by integrating this mixer filter with the rest of the circuit it is more economical than other conventional receivers.
  • Mohammad Veysi, Mohammad Reza Soltanpour Pages 23-40
    The camera stabilizer stabilizes the camera’s line of sight by isolating the camera from the model uncertainties, disturbances of operating environment and system movements. This paper presents a voltage-base optimal adaptive fuzzy sliding mode control for camera stabilizer. In this proposed control method, a voltage-base sliding mode controller is applied. But unfortunately, undesirable control input chattering is caused by employing the sliding mode control. In the following, for the prevention of incidence of the control input chattering, a first order TSK fuzzy approximator is employed. Although fuzzy sliding mode control prevents the chattering phenomenon, it has some disadvantages such as disability in estimating the bounds of the existing uncertainties and lack of stability proof of the closed-loop system. In what follows, to overcome the aforementioned problems, an adaptive fuzzy system is designed such that it can estimate the bounds of the existing uncertainties. Ultimately, the chicken swarm optimization algorithm is utilized to determine the optimal values of coefficients of the adaptive fuzzy sliding mode control and to decrease the control input amplitude. To investigate the desirable performance of the optimal adaptive fuzzy sliding mode controller, simulations in four steps are implemented on a camera stabilizer.
  • Golnaz Fattah, Nasser Masoumi Pages 41-54
    In this paper, we present a methodology to explore and evaluate the crosstalk noise and the profile of its variations, and the delay of interconnects through investigation of two groups of interconnect structures in nano scale VLSI circuits. The interconnect structures in the first group are considered to be partially coupled identical lines. In this case, by choosing proper values for different parameters, the crosstalk noise, when the victim line stays ahead of the aggressor line can be reduced up to 92% in comparison to when it is behind the aggressor line. The second group consists of a victim line shorter than the aggressor line. In this case, if the parameters are properly optimized, when the victim line is placed at the end of the aggressor line, the crosstalk noise can be reduced up to 86% in comparison to the case when the victim line is placed at the beginning.
  • Zeinab Mahdavipour Pages 55-61
    Solar cell is known as a sustainable and environment friendly source of energy in nature. It converts sunlight directly into electricity with zero emission and also without side-effects on the environment. But, solar cells have optical and mechanical defects which include the type of micro crack, the size of crack, and the noise from electrical or electromechanical interference during the image acquisition. This paper through image processing techniques presents several groups of methods to compare between two types of solar cell images, which are from solar cells with crack and without crack. In the first step, there are some methods such as Gaussian filter, Diffusion filter, Wavelet filter; Fast Fourier Transform and notch filter to de-noise images. In the next level, the study presents Gray Level Co-occurrence Matrix (GLCM) method to feature extraction of images and also the Hough transform to perform crack detection and analysis. Finally, the results confirm that the image from the solar cell with crack has the highest “S” measure compared to good images which have lower “S” measure levels.
  • M. Yousefi, Z. D. Koozehkanani, J. Sobhi Pages 63-69
    A 910MHz high efficiency RF transceiver for Wireless Body Area Network in medical application is presented in this paper. High energy efficiency transmitter and receiver architectures are proposed. In wireless body sensor network, the transmitter must have higher efficiency compared with the receiver because a large amount of data is sent from sensor node to receiver of the base station and smaller amount of data is received. Using colpitts oscillator in the proposed transceiver with injection-lock technique, the efficiency of transmitter and receiver has been improved. The designed transceiver consumes 1 mW at -6 dBm output with 5 Mbps data rate. Energy consumption of transmitter and receiver are 864 pJ/(bit×mW) and 114 pJ/bit, respectively. The proposed transmitter was designed in 0.18 µm RFCMOS technology.
  • Bahram Karimi, Mohammad Esmaeil Sadeghi Pages 71-78
    In this paper, a decentralized adaptive neural controller is proposed for a class of large-scale nonlinear systems with unknown nonlinear, non-affine subsystems and unknown nonlinear time-delay interconnections. The stability of the closed loop system is guaranteed through Lyapunov-Krasovskii stability analysis. Simulation results are provided to show the effectiveness of the proposed approaches.
  • Mohsen Ahmadi Mousavi, Behzad Moshiri, Zainabolhoda Heshmati Pages 79-88
    In this paper a new method is introduced for path planning of an autonomous vehicle. In this method, the environment is considered cluttered and with some uncertainty sources. Thus, the state of detected object should be estimated using an optimal filter. To do so, the state distribution is assumed Gaussian. Thus the state vector is estimated by a Kalman filter at each time step. The estimation of the probabilistic distribution can be shown using an error ellipse for a constant collision probability. Analytical forms of error ellipses can be obtained by quadratic inequalities. These quadratic inequalities make the optimization problem nonconvex. Thus, these inequalities are relaxed by applying a linearization approach. Finally, the optimization problem is reformulated to a convex optimization problem. There are some strong algorithms for solving a convex optimization problem, so the consequent path planning method can be solved efficiently with considerable performance that will be obtained in the end of this paper.
  • Hamid Radmanesh, Reza Sharifi, Amin Radmanesh, H. Fathi Pages 89-94
    This paper proposes novel Fuel Cell Auxiliary Power Unit (FCAPU) for J150 aircraft application. The primary version of APU in J150 aircraft is a gas turbine Auxiliary Power Unit (APU) which is based on gas turbine jet engine but in the suggested FCAPU, the generated electrical power is achieved from chemical energy with higher efficiency. The Solid Oxide Fuel Cell (SOFC) technology is used to generate the electrical energy and MATLAB software is applied to simulate the SOFC performance in the J150 aircraft. The simulation results show the FCAPU ability to generate the proper electrical energy with lower cost and higher reliability in comparison with the ordinary APU. Index Terms - Auxiliary Power Unit, Generator, Fuel Cell, Aircraft
  • Ebrahim Zareii, Mohsen Mohammadian, Ali Akbar Gharaveisi Pages 95-102
    This paper introduces a new approach for scheduling security constraint unit commitment (SCUC) including wind farms. Because of uncertainty in wind power production, we tried to develop a new method for incorporating wind power generation in power plant scheduling. For this, wind power generation modeled with unit commitment in a non-linear optimization problem and simulated by submitting different scenarios for wind farms. First, unit commitment solved in master problem. Then, scenarios for presenting volatile nature of wind power simulated. Numerical simulations show the effectiveness of supposed unit commitment for managing security of power system by considering volatility of wind power generation.
  • Turaj Amraee, Alireza Soroudi Pages 103-109
    This paper presents a voltage stability constrained optimal power flow that is expressed via a bilevel programming framework. The inner objective function is dedicated for maximizing voltage stability margin while the outer objective function is focused on minimization of total production cost of thermal units. The original two stage problem is converted to a single level optimization problem via the KKT optimality conditions. Here to assure that the KKT optimality conditions are both necessary and sufficient the original inner problem is replaced with an equivalent problem with different structure. The applicability of the proposed method is demonstrated by implementing it in IEEE-30 bus test system.
  • Hamid Radmanesh, Amir Heidary, Seyed Hamid Fathi, G.B. Gharehpetian Pages 111-117
    This paper proposes a novel Fault Current Limiter (FCL) for the application on distribution networks to control voltage sags at the Point of Common Coupling (PCC) during faults. This new FCL is based on series resonance including resonance transformer and series capacitor. So, by proper design of the series resonance LC tank, the fault current is limited to an acceptable level. The FCL operation is simulated using MATLAB software. In order to confirm the simulation results, a prototype structure is built and its measurement results are in agreement with the simulation results. The simulated and experimental results show that it is feasible to develop the FCL with low cost and high reliability.
  • S. M. Salehian, H. Hasanvand, B. Mozafari Pages 119-128
    In this paper, damping of interarea oscillations using simultaneous coordination of static Var compensator (SVC) and power system stabilizer (PSS) is considered. To be effective in damping of oscillations, the best-input signal of power oscillation damper (POD) associated with SVC is selected using Hankel singular values (HSVs), and right-hand plane zeros (RHP-zeros). The 4-machine-2 area standard test system, under different system configurations and loading conditions, is employed to illustrate the performance and robustness of the proposed controller. Eigenvalue analysis and nonlinear time domain simulation results demonstrate the effectiveness of the proposed technique to mitigate interarea oscillations under various operating conditions.