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Analysis and design of multi-stage wideband LNA using simultaneously noise and impedance matching method
, Article Microelectronics Journal ; Volume 86 , 2019 , Pages 97-104 ; 00262692 (ISSN) ; Medi, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
An analytical approach for design optimization of multi-stage LNAs with common source topology is developed. This paper reviews and analyses simultaneous noise and input impedance matching in three different topologies including common source amplifier with inductive degeneration, resistive feedback and dual feedback in order to achieve maximum available gain and minimum possible noise figure (NF). A study on multi-stage LNAs is performed to calculate optimum input impedance of each stage for minimum overall NF while considering the gain and NF of that stage in addition to the effect of noise of the following stages. MATLAB was used to calculate the starting point of design optimization in a...
A reconfigurable highly-linear CMOS transceiver core chip for X-band phased arrays
, Article AEU-International Journal of Electronics and Communications ; Volume 114 , February , 2020 ; Lotfi, H ; Medi, A ; Sharif University of Technology
Elsevier GmbH
2020
Abstract
This paper presents a highly-linear transceiver core chip for X-band phased-array systems with two RX and one TX channels. Implemented in a standard 0.18-μm CMOS technology, the core chip provides 6-bit phase control (with rms error <2°) and 6-bit gain control (with rms error <0.6 dB) both within the 8.5–11.5 GHz frequency band. Improved accuracy is also available by digital calibration in narrowband applications. The receivers achieve a gain of 13.5 dB, an IIP3 of +10.3 dBm, and a noise figure of 8.2 dB, while drawing 170 mA per channel from the 3.3 V supply. The chip also provides an additional low-gain mode which further enhances IIP3 to +19.1 dBm and the input-referred P1dB to +11.4 dBm....
Control of a nonlinear boiler- turbine unit using two methods: Gain scheduling & feedback linearization
, Article ASME International Mechanical Engineering Congress and Exposition, IMECE 2007, Seattle, WA, 11 November 2007 through 15 November 2007 ; Volume 9 PART A , 2008 , Pages 491-499 ; 0791843033 (ISBN); 9780791843031 (ISBN) ; Alasty, A ; Bakhtiari Nejad, F ; Sharif University of Technology
2008
Abstract
To achieve a good performance of a boiler-turbine unit, dynamic variables such as steam pressure, water level of drum and electric output of turbine must be controlled. In this paper a nonlinear model of the boiler-turbine unit is considered in which the inputs are the valve positions of fuel flow, steam control, and feed-water flow. Using two control methods, feedback linearization and gain scheduling, a PI controller is designed. It is shown that by applying both methods, system goes from one operating point to another with an appropriate specification of time response. Results show that system with a controller designed based on gain scheduling method has a better time response from a...
Effect of data traffic shaping on throughput and delay for VSG-CDMA cellular networks
, Article 2007 IEEE International Conference on Telecommunications and Malaysia International Conference on Communications, ICT-MICC 2007, Penang, 14 May 2007 through 17 May 2007 ; February , 2007 , Pages 6-11 ; 1424410940 (ISBN); 9781424410941 (ISBN) ; Ashtiani, F ; Sharif University of Technology
2007
Abstract
In this paper, we analyze the effect of applying leaky bucket as a well known traffic shaper on data users in a variable spreading gain CDMA (VSG-CDMA) uplink wireless cellular network. To this end, we model the effect of leaky bucket mechanism on a typical data user, with a closed product form queueing network. Each node in this queueing network corresponds to a specific processing gain or equivalently transmission rate and power. By solving such a queueing network we obtain the steady state probability with which a typical data user will exist at each node. By aggregating the effects of all data users we compute the mean and variance of interference and obtain the throughput and average...
Effects of bacillus amyloliquefaciens lfb112 on growth performance, carcass traits, immune, and serum biochemical response in broiler chickens
, Article Antibiotics ; Volume 10, Issue 11 , 2021 ; 20796382 (ISSN) ; Cheng, J ; Abbas, Z ; Cheng, Q ; Fan, Z ; Ahmad, B ; Hou, M ; Osman, G ; Guo, H ; Wang, J ; Zhang, R ; Sharif University of Technology
MDPI
2021
Abstract
This study aimed to investigate the effects of Bacillus amyloliquefaciens LFB112 on the growth performance, carcass traits, immune response, and serum biochemical parameters of broiler chickens. A total of 396 1 day old, mixed-sex commercial Ross 308 broilers with similar body weights were allotted into six treatment groups. The assigned groups were the CON group (basal diet with no supplement), AB (antibiotics) group (basal diet + 150 mg of aureomycin/kg), C+M group (basal diet + 5 × 108 CFU/kg B. amyloliquefaciens LFB112 powder with vegetative cells + metabolites), C group (basal diet + 5 × 108 CFU/kg B. amyloliquefaciens LFB112 vegetative cell powder with removed metabolites), M group...
Effects of bacillus amyloliquefaciens lfb112 on growth performance, carcass traits, immune, and serum biochemical response in broiler chickens
, Article Antibiotics ; Volume 10, Issue 11 , 2021 ; 20796382 (ISSN) ; Cheng, J ; Abbas, Z ; Cheng, Q ; Fan, Z ; Ahmad, B ; Hou, M ; Osman, G ; Guo, H ; Wang, J ; Zhang, R ; Sharif University of Technology
MDPI
2021
Abstract
This study aimed to investigate the effects of Bacillus amyloliquefaciens LFB112 on the growth performance, carcass traits, immune response, and serum biochemical parameters of broiler chickens. A total of 396 1 day old, mixed-sex commercial Ross 308 broilers with similar body weights were allotted into six treatment groups. The assigned groups were the CON group (basal diet with no supplement), AB (antibiotics) group (basal diet + 150 mg of aureomycin/kg), C+M group (basal diet + 5 × 108 CFU/kg B. amyloliquefaciens LFB112 powder with vegetative cells + metabolites), C group (basal diet + 5 × 108 CFU/kg B. amyloliquefaciens LFB112 vegetative cell powder with removed metabolites), M group...
Design & Implementation of Test circuit for an array of sensor Diodes in Low Temperature (77K)
, M.Sc. Thesis Sharif University of Technology ; Medi, Ali (Supervisor) ; Fardmanesh, Mahdi (Supervisor)
Abstract
A Focal Plane Array (FPA) consists of one or two dimensional array of sensor elements and is widely used in imaging systems. Generally an FPA can be divided into two main parts: Sensor array and read-out/test circuit. In this thesis we design and implement a test circuit for an FPA that works in 77K. The circuit will be attached to the sensor to detect and amplify its very low level current that is in the range of 10 pA to more than 10 nA. Reducing MOSFET temperature from room temperature (300K) down to liquid nitrogen (77K) will greatly changes its parameters and characteristics such as Threshold Voltage and carrier mobility. However MOSFET models in low temperature are either...
Evaluation of Several Design Methods of Nonlinear Observers and Comparing their Performances
, M.Sc. Thesis Sharif University of Technology ; Shahrokhi, Mohammad (Supervisor)
Abstract
The main objective of this study is evaluation of several nonlinear observers and comparing their performances.First, the literature review is presented; and then the process model is described. Second, observability and the observer design is disscused. Performances of Lunberger, sliding, and high gain nonlinear observers have been compared. Finally, the performance of a high gain observer in a closed-loop system including the back stepping controller has been evaluated.
Fractional PI Tuning for the First Order Plus Dead Time Processes
, M.Sc. Thesis Sharif University of Technology ; Tavazoei, Mohammad Saleh (Supervisor)
Abstract
In this thesis, a new method has been developed for tuning of fractional PI ( ) and fractional [PI] ( ) controllers for the first order plus dead-time ( ) systems. By using the performance-map method ( ) and based on phase and gain margins' criteria, a formula which is function of fractional order ( ) and normalized dead-time ( ) has been proposed for the proportional and integral coefficients. In addition, an equation has been given for the fractional order of controller to minimize the integrated absolute error ( ) index. Moreover, overshoot and settling-time of the step response of the system have been improved by dynamic setpoint weighting. Simulation results have shown that proposed...
Design of a UWB Reconfigurable LNA with Variable Gain
, M.Sc. Thesis Sharif University of Technology ; Atarodi, Mojtaba (Supervisor) ; Fotowat Ahmady, Ali (Supervisor)
Abstract
In recent years, lots of efforts has been done to implement Ultra-Wideband (UWB) Low Noise Amplifiers (LNAs), and Reconfigurable Low Noise Amplifiers, to achieve low Noise Figure (NF) and power dissipation, and high gain and linearity. In this thesis an Ultra-Wideband CMOS Low Noise Amplifier is presented. Due to really low power consumption and extremely high data rates, the UWB standard is popular in the consumer market. The LNA is the outer most part of an UWB transceiver, which provides enough gain to the signal with the least possible noise and distortion. 0.18u CMOS technology has been chosen for the design of the LNA at the transistor level. Two different bandwidths in a single LNA...
Design of Digital Backend of the RFID Reader and Design of Baseband Signal Conditioning Circuits and Simulating RFID System
, M.Sc. Thesis Sharif University of Technology ; Sharif Bakhtiar, Mehrdad (Supervisor)
Abstract
In this Thesis, first, UHF RFID Class1 Generation 2 was studied accurately and Required Signaling, Timing and Circuit Parameters for Design Readers in this Band, was Extracted from Standard. an important algorithm for Tags inventory, that Protocol leaves the way of implementation to designer, was introduced and simulated. Also a effective method was presented that detect bit streams received by readers in low SNR. Some parts of Baseband Signal conditioning circuits, including filter and variable gain amplifier, wad designed in 0.18 um CMOS Technology. In Second part, communication protocol between server and readers was introduced with some Scenarios that make communication easier and make...
The Impact of the Complementarity of Factors of Production on the Welfare Gains from International Trade
, M.Sc. Thesis Sharif University of Technology ; Madanizadeh, Ali (Supervisor)
Abstract
To answer how large the welfare gains from international trade are, this thesis uses two main ideas: linkages and complementarity. A problem along the production chain can sharply reduce output under complementarity. In such a circumstance, international trade and importing in the sectors which are the weak links of the production chain, help solve this problem. Using a general equilibrium model, it is shown that, the complementarity of the intermediate goods assumption results in much higher welfare gains from international trade compared to similar international trade models which assume the substitutability of the intermediate goods
Design and Implimentation of an Online Robust Model Predictive Controller for Stabilization and Transparency of Sinus Surgery Haptic Simulator
, M.Sc. Thesis Sharif University of Technology ; Vossoughi, Gholamreza (Supervisor) ; Moradi, Hamed (Supervisor)
Abstract
No one bears thinking about undergoing a surgery by an unexpirienced surgeon, the consideration of which implies the prominence of effective surgical trainings. The advent of utilizing haptic interfaces as a novelty in this field has led to a more promising surgery education. These haptic interfaces consist of three communicating parts namely: operator’s hand, haptic robot, and tissue virtual environment. Design and implementation of a proper controller in order to stabilize the haptic interface during surgery simulation, with acceptable transparency, is still novel an otherwise challenging research field. In this thesis we consider an appropriate nonlinear model for both virtual tissue as...
Design and Implementation of a Low Phase Noise Oscillator using Oversized Cavity Resonator
, M.Sc. Thesis Sharif University of Technology ; Banai, Ali (Supervisor)
Abstract
The aim of doing this project is design and fabrication of a X band low phase noise oscillator Using oversized cavity resonator and transposed gain amplifier.One of the most important factors in reducing oscillators phase noise is the quality factor of its resonator and by increasing the quality factor, we can reduce the phase noise. So by doing this , in this project we want to increase the quality factor of the resonator part of the oscillator and design an oscillator in the X frequency band ( approximately 8 GHz ) .As we know the Q factor for waveguide cavity resonator is increased when we use them in the higher order modes and there is a great improvement in Q factor T when we use them...
Decentralized Integral Controller Design to Possess Integrity
, M.Sc. Thesis Sharif University of Technology ; Nobakhti, Amin (Supervisor)
Abstract
Design of fault tolerant controllers with a reliable and robust control structure that can accommodate sensor and actuator failure is a challenging problem. In the process control literature, the term “integrity” is used to characterize these properties for decentralized control systems. It refers to the ability to retain system stability when one or some of the control loops get in or out of service or when loop gains are detuned.Conditions pertaining to the integrity of the closed-loop system are described by a series of successively more difficult to attain criteria whose evaluation is only based on the process steady state gains. These are Integral stabilizibility (IS), Integral...
Analytical Design of Fixed-structure Fractional-order Controllers in Frequency Domain
, Ph.D. Dissertation Sharif University of Technology ; Tavazoei, Mohammad Saleh (Supervisor)
Abstract
Due to the simplicity and generality, design of feedback control systems in the frequency domain is among the most prominent topics in the control systems engineering. The problem of compensation means properly adjusting the loop frequency response at critical frequencies. Considering the point that the traditional methods usually use trial and error procedures for compensation, analytical design of fixed-structure controllers for exactly adjusting such values has great importance. Benefitting from the capability of fractional-order dynamics, the compensation problem is studied from three aspects in this thesis. At first according to the importance of adjusting the system frequency response...
Opportunistic RF Energy Harvesting in Cognitive Radio Networks
, M.Sc. Thesis Sharif University of Technology ; Nasiri-kenari, Masoumeh (Supervisor) ; Ashtiani, Farid (Supervisor)
Abstract
Considering energy efficiency ways a key role in designing future wireless networks( 5G mobile networks). Moreover Spectrum efficiency is another critical issues in designing wireless networks. Cognitive radios can improve the spectrum efficiency. On the other hand, radio frequency (RF) energy harvesting has emerged as a promising technique to supply energy for wireless networks and thereby increase their energy efficiency. In this thesis, we propose a new technique for the RF-powered CRNs.To this end,We consider a cognitive radio network comprised of a primary user and a secondary user. The primary user, uses a typical frequency band for transmit data in a time slot basis and both the...
Simulation and Control of a Nonlinear and Non-Minimum Phase Bioreactor
, M.Sc. Thesis Sharif University of Technology ; Shahrokhi, Mohammad (Supervisor)
Abstract
Control of fermentation bioreactors with nonlinear behavior is a very important issue, especially when optimizing the biomass production is desired. The system in this situation works in two domains: minimum phase and non-minimum phase; and in transition from one domain into the other one the sign of process gain changes. For control of such a process in this work have been used two non-adaptive strategies and one adaptive strategy. The non-adaptive schemes are pole-placement and model predictive. The pole-placement technique as a linear control algorithm is used and its parameters are fixed by minimizing the objective function which has been used in predictive control technique. Another...
Damping Controller Design for Inter-area Oscillations Using Wide-area Measurements
, Ph.D. Dissertation Sharif University of Technology ; Ranjbar, Ali Mohammad (Supervisor)
Abstract
The wide-area damping controller (WADC) has been proposed to enhance the damping of inter-area oscillations. The most challenging deficiencies to make this controller practical are the power system operating condition changes and the inherent time delay of remote signals. They can deteriorate the controller performance and the whole system stability if not properly accounted for in the design procedure. This thesis presents an adaptive delay compensator (ADC) on the basis of the latest development in the wide-area measurement system (WAMS) to cater to varying latencies. The proposed compensator can effectively reciprocate the phase deviation resulting from varying delays to improve the...
Higher-Order Sinusoidal Input Describing Function, Based Analysis of Hybrid Integrator-Gain Control Systems
, M.Sc. Thesis Sharif University of Technology ; Tavazoei, Mohammad Saleh (Supervisor)
Abstract
Linear controllers have become popular in the industry because they have a simple structure and are easily implemented. But, they have fundamental limitations like waterbed effect and Bode’s phase gain relation. To overcome these limitations, other types of controllers have to be used like nonlinear controllers and reset ones. The hybrid integrator-gain system (HIGS) is one of these systems that has been able to overcome these limitations very well.Partial resetting and achieving variable phase in output are essential features in reset systems that have not been developed in HIGS. Here we are interested in generalizing HIGS to accomplish these features.Calculating higher-order harmonics is...