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distributed-amplifier
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Design of a 2-12-GHz bidirectional distributed amplifier in a 0.18- mu m CMOS technology
, Article IEEE Transactions on Microwave Theory and Techniques ; Volume 67, Issue 2 , 2019 , Pages 754-764 ; 00189480 (ISSN) ; Meghdadi, M ; Yaghoobi, M ; Medi, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
This paper presents the design and implementation of a bidirectional distributed amplifier (BDDA) in a 0.18- boldsymbol mu ext{m} CMOS process. The performance of the BDDA is theoretically analyzed, and the optimum number of gain stages ( n-{ ext {opt}} ), maximum achievable power gain ( G-{P} ), and circuit bandwidth are formulated. In addition, a new formula for proper choice of the number of DA stages (i.e., n ) is offered where dc-power consumption of the circuit ( P-{ ext {dc}} ) is also considered. This formula optimizes G-{P}/P-{ ext {dc}} , and it is preferred over the conventional n-{ ext {opt}} formula. To validate the theoretical analyses, a 2-12-GHz BDDA with high output 1-dB...
The Stability Analysis of Distributed Amplifier
,
M.Sc. Thesis
Sharif University of Technology
;
Medi, Ali
(Supervisor)
Abstract
Advancement in the field of electronics can often be observed from the improvement in performance of active circuits and systems. The amplifier, because it is a highly versatile functional circuit, has always been one of the first to benefit from new developments. Of the many characteristic of an amplifier, perhaps the most notable are the gain and the frequency response. In many applications, both the gain and the bandwidth need to be optimized. One of the most significant structures which have proper gain and bandwidth, are distributed amplifiers. But these structures are nonsymmetrical and have many active loops. As a result, the stability analysis of distributed amplifier is quite...
Design and Implementation of X-Ku Band Variable Gain Amplifier in CMOS Technology
, M.Sc. Thesis Sharif University of Technology ; Medi, Ali (Supervisor)
Abstract
In this thesis, a new wide band variable gain distributed amplifier (VGDA) is presented. A novel approach to implement uniform gain control in the wide band frequency range of 8 – 18 GHz is demonstrated. A different technique has been employed to provide necessary DC bias current, avoiding large DC-Feed inductors. A five-section wideband VGDA has been designed and fabricated in 0.18 μm CMOS technology. The VGDA have a flat gain of 11 dB, noise figure better than 5 dB, P1dB of 14 dBm at the output, input and output matching better than -12 dB and -14 dB, respectively, for maximum gain state over the 10 GHz UWB band. The gain control range is between 3 – 11 dB with gain steps of 0.5 dB and rms...
Design and Implementation of Integrated Broadband Low-Noise Amplifier
, Ph.D. Dissertation Sharif University of Technology ; Medi, Ali (Supervisor)
Abstract
Broadband low-noise amplifiers (LNAs) find widespread application in many communication and measurement systems, and extensive research efforts have been devoted to improve their performances. The main efforts include the system bandwidth enhancement for increasing the data rate, the system noise reduction for improving sensitivity of receivers, and lowering the power consumption for increasing battery life of handheld systems. There is a steady quest to develop novel circuit architectures and design methodologies that can pave the way for performance enhancement of overall system.In this thesis, the design and implementation of a broadband low-noise amplifier circuit is investigated. The...
Stabilisation of multi-loop amplifiers using circuit-based two-port models stability analysis
, Article IET Circuits, Devices and Systems ; Volume 15, Issue 6 , 2021 , Pages 553-559 ; 1751858X (ISSN) ; Meghdadi, M ; Medi, A ; Sharif University of Technology
John Wiley and Sons Inc
2021
Abstract
This article applies a systematic approach based on the normalized determinant function (NDF) theory to analyse stability in multi-loop circuits and to design the required stabilization network. Presenting several provisions, the return ratios are extracted by employing immittance or hybrid matrices (Z, Y, G or H) of active two ports. Using these matrices, instead of the S-parameters, facilitates the selection of an appropriate stabilizer network. As a practical case, a non-uniform distributed amplifier (NDA) is designed and inspected for potential instabilities. The presented procedure detects instability associated with one of the NDA circuit's loops, and an appropriate stabilization...
FDTD analysis of distributed amplifiers based on the fully distributed model
, Article 2007 Asia-Pacific Conference on Applied Electromagnetics, APACE2007, Melaka, 4 December 2007 through 6 December 2007 ; 2007 ; 1424414350 (ISBN); 9781424414352 (ISBN) ; Abdipour, A ; Shishegar, A. A ; Sharif University of Technology
2007
Abstract
In this paper a wave approach has been introduced to study the performance of a distributed amplifier. The time domain response of a FET is obtained by means of the fully distributed model. By applying the procedure to a pi-gate GaAs MESFET, the S matrix is computed from time domain results over a frequency range of 2-20 GHz. Scattering parameters of gate and drain lines are extracted from three-dimensional FDTD simulation. The result obtained by this wave approach is compared with device lumped model and Quasi static approach of transmission line. © 2007 IEEE
Design of Front End of UWB Receivers
, M.Sc. Thesis Sharif University of Technology ; Sadughi, Sirous (Supervisor) ; Haj Sadeghi, Khosro (Supervisor)
Abstract
This Project deals with the Low-Noise Amplifier (LNA) and High-Q Band-Stop filter for a UWB receiver designed using a standard 0.18um CMOS process. These LNAs cover the frequency band of 1 to 11 GHz. Stringent sensitivity and low noise figure requirements, presence of strong in-band interferers and the ultra wide band operation are the main design challenges of the receiver and the LNA. In this thesis, Three LNAs with good performance and good input matching are designed. Two of them used Common gate topology with gm-Boosting technique to reduce the noise figure. Also because of wide bandwidth requirement, the bandwidth of these LNAs is improved by Inductive shunt and series peaking...
A Multioutput and Highly Efficient GaN Distributed Power Amplifier for Compact Subarrays in Wideband Phased Array Antennas
, Ph.D. Dissertation Sharif University of Technology ; Atarodi, Mojtab (Supervisor)
Abstract
New applications such as high data rate telecommunications, millimeter-wave imaging systems, positioning systems, wall, and ground-penetrating radars, and vital sign monitoring radars require specifications of heavy-duty systems. In summary, in advanced applications with high bandwidth, having multiple inputs and multiple outputs, phased arrays, and optimal energy efficiency are in demand and desirable. Despite the diverse applications of these radars, commercial products in this field are very rare, expensive, and bulky. Therefore, research work in this area is justified from an applied perspective. Increasing the power amplifier's efficiency results in the creation of a smaller, more...
Unilateralization of MMIC distributed amplifiers
, Article IEEE Transactions on Microwave Theory and Techniques ; Vol. 62, issue. 12 , 2014 , pp. 3041-3052 ; ISSN: 00189480 ; Medi, A ; Sharif University of Technology
Abstract
This paper presents an unilateralization technique for distributed amplifiers (DAs) based on the transformer coupling between the gate and drain lines. Theoretical analysis of the DA indicates that the voltage waves in the gate and drain lines can be described by a system of linear partial differential equations. The transformer coupling between the lines allows for cancellation of the reverse transmission coefficient of the system. There is an optimal value for the coupling coefficient between the lines that unilateralizes the DA. This optimal coupling coefficient is derived in terms of the gate-drain capacitance and capacitances of the gate and drain lines. Using the proposed technique,...
A 40-GHz bandwidth tapered distributed LNA
, Article IEEE Transactions on Circuits and Systems II: Express Briefs ; 2017 ; 15497747 (ISSN) ; Medi, A ; Sharif University of Technology
Abstract
In this brief, a design technique for tapered distributed low-noise amplifiers (LNAs) is presented. A circuit model is developed for gain and noise analysis of a nonuniform distributed amplifier (DA). It is shown that by optimal tapering of gate and drain transmission lines and transistors, the tapered distributed LNA can provide lower broadband average noise figure (NF) compared to a uniform DA. A proof-of-concept integrated circuit is implemented using a 0.1-μm GaAs pHEMT process. The amplifier provides average gain of 15.2 dB and 3-dB bandwidth of 43.3 GHz. The average NF of 2.3 dB and minimum NF of 2.0 dB are achieved over 2–40 GHz. The chip consumes 55 mA current from a 2-V supply. IEEE...
A 40-GHz bandwidth tapered distributed LNA
, Article IEEE Transactions on Circuits and Systems II: Express Briefs ; Volume 65, Issue 11 , 2018 , Pages 1614-1618 ; 15497747 (ISSN) ; Medi, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
In this brief, a design technique for tapered distributed low-noise amplifiers (LNAs) is presented. A circuit model is developed for gain and noise analysis of a nonuniform distributed amplifier (DA). It is shown that by optimal tapering of gate and drain transmission lines and transistors, the tapered distributed LNA can provide lower broadband average noise figure (NF) compared to a uniform DA. A proof-of-concept integrated circuit is implemented using a 0.1-μm GaAs pHEMT process. The amplifier provides average gain of 15.2 dB and 3-dB bandwidth of 43.3 GHz. The average NF of 2.3 dB and minimum NF of 2.0 dB are achieved over 2-40 GHz. The chip consumes 55 mA current from a 2-V supply. ©...