Nonlinear Systems in Electrical Engineering
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Journal of Nonlinear Systems in Electrical Engineering - Journal articles for year 2020, Volume 6, Number 2Yektaweb Collection - https://yektaweb.comen2020/2/12Design and Simulation of a Fluidic Micro-Bio-Sensor Based on Resonator Array
http://jnsee.sut.ac.ir/jnsee/browse.php?a_id=228&sid=1&slc_lang=en
In this paper, a fluidic biosensor with possibility to fabricate by Micro-Electro-Mechanical Systems (MEMS) technology is proposed for biomedical mass detection and lab-on-chip applications. This is designed by electromechanical coupling of harmonic micromechanical resonators with harmonic springers as a mechanical resonator array. It can disperse mechanical wave along the array by electrostatic method using interdigitate capacitors as actuators and sensors. It has some vital advantages like: low cost fabrication method, low fluidic interference damping effect, and high sensitivity with large absorbent area. In order to estimate the sensitivity of the proposed biosensor against the mass perturbation, the measurability of capacitance changes and fluidic interference damping effect, the stimulated analysis is conducted by COMSOL. It results, a suitable sensitivity and possibility to measure the biosensor outputs by available electronic instrumentations.Mousa ShamsiDesign of an Efficient Circuit for Data Rate Configuration in Power Amplifier Dedicated to Wireless Medical Applications
http://jnsee.sut.ac.ir/jnsee/browse.php?a_id=254&sid=1&slc_lang=en
This paper presents a new circuit to configure power amplifier (PA) for return-to-zero on-off-keying (RZ-OOK) transmitters. The proposed PA works as a multimode structure with configurable data rate and output power. The programmable data rate function is achieved by duty cycle adjustment of input data and producing input RZ-data by a simple circuit, which leads to a linear scale of data rate with power consumption. This implies that any desired level of output power can be transmitted with different power consumption according to the power budget. The RZ-data is also utilized to perform the output power reconfiguration. The PA represents data rate of 0.3Mb/s to 3Mb/s and it can deliver output power level from -23dBm to 0dBm. During data rate adjustment, power consumption varies from 0.099mW to 0.99mW when the output power is 0dBm. Also, PA consumes 0.07mW to 0.99mW at the output power tuning range with a data rate of 3Mb/s.Esmaeil Najafi Aghdam Analyzing the Effect Adding an Active Feedback Network with an Inductive behavior to a Common-Gate Topology as a Transimpedance Amplifier for Low-Power and Wide-Band Communication Applications
http://jnsee.sut.ac.ir/jnsee/browse.php?a_id=306&sid=1&slc_lang=en
Common Gate (CG) topologies are commonly used as the first stage in Transimpedance Amplifiers (TIA), due to their low input resistance. But, this structure is not solely used as a TIA and comes with other topologies such as differential amplifiers or negative resistances and capacitances. This paper deals with analyzing the effect of adding an active feedback network to a common gate topology. Generally, the feedback network is used to reduce the input resistance of the CGs topology, but in this paper it is shown that an active feedback network, which occupies a small area, not only reduces further the input resistance of CG topologies, but also forms an active inductive behavior, which can be used to resonate with the large parasitic capacitance of the photodiode and hence obtain a wide bandwidth. Mathematical analysis is done in this paper to prove the existence of this active inductor, which is also proved in the simulations. Finally, it is shown that this stage alongside its active feedback can be used as a high-speed and low-power transimpedance amplifier for optical communication applications.Soorena ZohooriForward kinematic analysis of planar parallel robots using a neural network-based approach optimized by machine learning
http://jnsee.sut.ac.ir/jnsee/browse.php?a_id=263&sid=1&slc_lang=en
The forward kinematic problem of parallel robots is always considered as a challenge in the field of parallel robots due to the obtained nonlinear system of equations. In this paper, the forward kinematic problem of planar parallel robots in their workspace is investigated using a neural network based approach. In order to increase the accuracy of this method, the workspace of the parallel robot is divided into a number of smaller subspaces using the classifier and the boundary overlap method. After estimating the corresponding subspace, two separate neural networks are used in each subspace to determine the position and orientation of the moving platform. This approach is implemented on a 3-<u>P</u>RR planar parallel robot and its results are compared with the results obtained from the MLP, WaveNet, GMDH, Dual and Independent neural networks. Moreover, in order to evaluate the efficiency of the proposed method, a circular motion path is simulated using this approach and its performance is compared with the five mentioned methods. The results obtained from the implementation of this approach and comparison with the conventional methods indicates that the proposed method analyzes the forward kinematic problem of planar parallel robot with proper accuracy.Hassan KhotanlouA Linear Matrix Inequality Approach to Design Robust Model Predictive Control for Nonlinear Uncertain Systems Subject to Control Input Constraint
http://jnsee.sut.ac.ir/jnsee/browse.php?a_id=282&sid=1&slc_lang=en
<span style="left: 230.402px; top: 479.623px; font-size: 13.927px; font-family: serif; transform: scaleX(0.934108);">In this paper, a robust model predictive control (MPC) algorithm is designed for </span><span style="left: 194.679px; top: 498.09px; font-size: 13.927px; font-family: serif; transform: scaleX(0.938306);">nonlinear uncertain systems in presence of the control input constraint. To achieve this </span><span style="left: 194.679px; top: 516.404px; font-size: 13.927px; font-family: serif; transform: scaleX(0.998729);">goal, first, the additive and polytopic uncertainties are formulated in the nonlinear </span><span style="left: 194.676px; top: 534.725px; font-size: 13.927px; font-family: serif; transform: scaleX(0.933634);">uncertain system. Then, the control policy is chosen as a state feedback control law in </span><span style="left: 194.676px; top: 553.042px; font-size: 13.927px; font-family: serif; transform: scaleX(1.0205);">order to minimize a given cost function at each known sample</span><span style="left: 548.144px; top: 553.042px; font-size: 13.927px; font-family: serif; transform: scaleX(1.02384);">-time. Finally, the robust </span><span style="left: 194.662px; top: 571.356px; font-size: 13.927px; font-family: serif; transform: scaleX(0.953587);">MPC problem is transformed into another optimization problem subjec</span><span style="left: 598.546px; top: 571.356px; font-size: 13.927px; font-family: serif; transform: scaleX(0.907662);">t to some linear </span><span style="left: 194.662px; top: 589.824px; font-size: 13.927px; font-family: serif; transform: scaleX(0.943515);">matrix inequality (LMI) constraints. The controller gains are determined via the online </span><span style="left: 194.662px; top: 608.138px; font-size: 13.927px; font-family: serif; transform: scaleX(0.960302);">solution of the proposed minimization problem in real</span><span style="left: 507.268px; top: 608.138px; font-size: 13.927px; font-family: serif; transform: scaleX(0.951479);">-time. The suggested method is </span><span style="left: 194.662px; top: 626.452px; font-size: 13.927px; font-family: serif; transform: scaleX(0.948238);">simulated for a second order nonlinear uncertain system. The closed-</span><span style="left: 588.56px; top: 626.452px; font-size: 13.927px; font-family: serif; transform: scaleX(0.952897);">loop performance </span><span style="left: 194.662px; top: 644.766px; font-size: 13.927px; font-family: serif; transform: scaleX(0.948565);">is compared to other control techniques. The simulation results show the effectiveness </span><span style="left: 194.662px; top: 663.233px; font-size: 13.927px; font-family: serif; transform: scaleX(0.997118);">of the proposed algorithm compared to some existing control methods.</span><br>
Valiollah GhaffariAntenna Design and Non Linear Simulation of Rectifier for Wideband and Multi-Tone Radio Frequency Energy Harvesting
http://jnsee.sut.ac.ir/jnsee/browse.php?a_id=309&sid=1&slc_lang=en
In this paper, a wideband rectenna without using matching networks is presented. In addition of wide bandwidth, the omnidirectional radiation pattern, maximum radio frequency to dc conversion efficiency, harvesting capability of the minimum input power level, easy fabrication process cause this antenna be a good choice for radio frequency energy harvesting applications. Matching network has been eliminated and the antenna structure has been used to match with rectifier for energy harvesting with maximum efficiency. Based on the minimum input power level, two different structures have been suggested as the rectenna. The suggestive model meets proper efficiency within the frequency band of 1.71-2.5GHz and harvests the input power levels of 0dBm and -5dBm by implementing the two proposed structures with the maximum efficiencies of 74 and 68%, respectively. The multi-tone state has been also investigated which indicated the maximum obtained efficiencies of about 42 and 44% for the 2- and 3-tone modes, respectively.Seyed Mohammad Hashemi