DOCSLIB.ORG

High-Frequency Oscillator Design with Independent Gate Finfet a Thesis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
High-Frequency Oscillator Design with Independent Gate Finfet a Thesis High-Frequency Oscillator Design with Independent Gate FinFET A thesis presented to the faculty of the Russ College of Engineering and Technology of Ohio University In partial fulfillment of the requirements for the degree Master of Science Yunus Kelestemur December 2019 © 2019 Yunus Kelestemur. All Rights Reserved. 2 This thesis titled High-Frequency Oscillator Design with Independent Gate FinFET by YUNUS KELESTEMUR has been approved for the School of Electrical Engineering and Computer Science and the Russ College of Engineering and Technology by Savas Kaya Professor of Electrical Engineering Mei Wei Dean, Russ College of Engineering and Technology 3 ABSTRACT YUNUS KELESTEMUR, M.S., December 2019, Electrical Engineering and Computer Science High-Frequency Oscillator Design with Independent Gate FinFET Director of Thesis: Savas Kaya There is an increasing demand for wireless communication because of its convenience for the system-on-chip (SoC) paradigm that integrates the whole system on a single chip. Most of SoC applications such as 5G mobile network, car radar, network-on- chip (NoC) communication require high-frequency oscillators. In particular, the wireless links that can be adapted for on-chip communication can greatly expand the power and latency concerns in future many-core (64 and above) computers. The transmitters in the NoC routers would need very high-frequency wireless channels that must be driven by extremely compact and efficient oscillators that can operate as high as 500 GHz. In this thesis, two high-frequency voltage-controlled oscillators are presented without using any varactors to control the frequency of oscillation. The independent gate (IG) FinFETs are used to tune the oscillation frequency of the oscillators and simulations are carried out using Cadence Virtuoso design tools and BSIM-IMG transistor models inserted into a 65 nm RF-CMOS design kit. The first oscillator design is based on Colpitts architecture using 65 nm IG-FinFETs. The oscillator has 165 GHz oscillation frequency with 3% tunability. The power consumption of the oscillator is 50mW and the area is less than 0.001mm2. The phase noise of the oscillator at 1 MHz is -70 dBc/Hz. The second oscillator design is based on the cross-coupled push-push oscillator 4 architecture using 45 nm IG-FinFETs. The oscillator has 250 GHz oscillation frequency with 2% tunability. The power consumption of the oscillator is 12 mW and the area is less than 0.01mm2. The phase noise of the oscillator at 1 MHz is -82 dBc/Hz. Besides the novel oscillator topologies and their encouraging performance figures, this work also incorporates several other unique aspects, including the use of BSIM-IMG based models in connection with an RF-CMOS design kit, utilization of tunable transistor parasitics for VCO design and incorporation of accurate modeling of 3D inductors obtained via 3D electro-magnetic solvers into the circuit analysis. Although the performance predictions are limited by the finite accuracy of the BSIM model at such elevated frequencies and by the lack of detailed layout rules for the IG-FinFETs, the work performed in this thesis lends strong credence to this transistor architecture for compact circuit development in analog mm-wave circuits in general and SoC wireless applications in particular. 5 TABLE OF CONTENTS Page Abstract ...........................................................................................................................3 List of Tables...................................................................................................................7 List of Figures .................................................................................................................8 Chapter 1 : Introduction ...................................................................................................9 1.1 Overview .............................................................................................................9 1.2 Thesis Objectives ............................................................................................... 12 1.3 Thesis Contributions and Layout ........................................................................ 12 Chapter 2 : Background ................................................................................................. 13 2.1 MOSFET ........................................................................................................... 13 2.1.1 Operation .................................................................................................. 14 2.1.2 Current-Voltage(I-V) Characteristics ......................................................... 15 2.1.3 High-Frequency Model.............................................................................. 17 2.1.4 Derivatives of MOSFET ............................................................................ 20 2.2 IG-FinFET ......................................................................................................... 22 2.2.1 Operation .................................................................................................. 22 2.3 Oscillators .......................................................................................................... 25 2.3.1 Phase Noise ............................................................................................... 26 2.4 Simulation tools ................................................................................................. 27 2.4.1 Cadence Virtuoso CAD Environment ........................................................ 28 2.4.2 BSIM ........................................................................................................ 28 2.4.3 Keysight Advanced Design Systems .......................................................... 30 Chapter 3 : Colpitts Oscillator Design ............................................................................ 32 3.1 Colpitts Oscillator .............................................................................................. 32 3.2 Design with IG-FinFET ..................................................................................... 33 3.3 Simulation Results and Analysis ........................................................................ 36 3.4 Summary ........................................................................................................... 40 Chapter 4 : Cross coupled Push-Push Oscillator Design ................................................. 41 4.1 Cross Coupled Push-Push Oscillator .................................................................. 41 4.2 Design with IG-FinFET ..................................................................................... 44 4.3 Simulations Results and Analysis ....................................................................... 46 6 4.4 Summary ........................................................................................................... 51 Chapter 5 : Conclusions and Future Work ...................................................................... 52 5.1 Conclusions ....................................................................................................... 52 5.2 Future Work ....................................................................................................... 56 References ..................................................................................................................... 58 Appendix A: BSIM Model File ...................................................................................... 63 Appendix B: Netlist Files............................................................................................... 65 Appendix C: Papers Contributed During The Course of This Degree ............................. 67 7 LIST OF TABLES Page Table 5.1 : Similar contemporary oscillators .................................................................. 54 8 LIST OF FIGURES Page Figure 2.1 : Top view of thin-body n-Channel MOSFET .............................................. 15 Figure 2.2 : Drain current vs Drain source voltage ........................................................ 16 Figure 2.3 : Low-frequency small-signal model of MOSFET ........................................ 18 Figure 2.4 : Parasitic capacitances of a MOSFET .......................................................... 19 Figure 2.5 : High-frequency small-signal model of a MOSFET ..................................... 20 Figure 2.6 : a) SOI FinFET, b) SOI tri-gate MOSFET, c) SOI π-gate MOSFET, d) SOI Ω-gate MOSFET, e) SOI gate-all-around MOSFET, f) bulk tri-gate MOSFET ............. 21 Figure 2.7 : IG-FinFET device structure ....................................................................... 23 Figure 2.8 : Oscillator system ........................................................................................ 25 Figure 3.1 : Colpitts oscillator simplified biasing .......................................................... 32 Figure 3.2 : Modified Colpitts oscillator with IG-FinFET ............................................. 34 Figure 3.3 : Small signal model of the modified Colpitts oscillator ............................... 35 Figure 3.4 : IV curves of 65 nm IG FinFET with different back-gate bias ..................... 37 Figure 3.5 : Change in oscillation frequency with back-gate bias voltage ...................... 37 Figure 3.6 : Effects of gate width and length on oscillation frequency, power consumption and tuning range of the oscillator ............................................................
Load more

Recommended publications
  • Forced Mechanical Oscillations
    169 Carl von Ossietzky Universität Oldenburg – Faculty V - Institute of Physics Module Introductory laboratory course physics – Part I Forced mechanical oscillations Keywords: HOOKE's law, harmonic oscillation, harmonic oscillator, eigenfrequency, damped harmonic oscillator, resonance, amplitude resonance, energy resonance, resonance curves References: /1/ DEMTRÖDER, W.: „Experimentalphysik 1 – Mechanik und Wärme“, Springer-Verlag, Berlin among others. /2/ TIPLER, P.A.: „Physik“, Spektrum Akademischer Verlag, Heidelberg among others. /3/ ALONSO, M., FINN, E. J.: „Fundamental University Physics, Vol. 1: Mechanics“, Addison-Wesley Publishing Company, Reading (Mass.) among others. 1 Introduction It is the object of this experiment to study the properties of a „harmonic oscillator“ in a simple mechanical model. Such harmonic oscillators will be encountered in different fields of physics again and again, for example in electrodynamics (see experiment on electromagnetic resonant circuit) and atomic physics. Therefore it is very important to understand this experiment, especially the importance of the amplitude resonance and phase curves. 2 Theory 2.1 Undamped harmonic oscillator Let us observe a set-up according to Fig. 1, where a sphere of mass mK is vertically suspended (x-direc- tion) on a spring. Let us neglect the effects of friction for the moment. When the sphere is at rest, there is an equilibrium between the force of gravity, which points downwards, and the dragging resilience which points upwards; the centre of the sphere is then in the position x = 0. A deflection of the sphere from its equilibrium position by x causes a proportional dragging force FR opposite to x: (1) FxR ∝− The proportionality constant (elastic or spring constant or directional quantity) is denoted D, and Eq.
    [Show full text]
  • Analysis of BJT Colpitts Oscillators - Empirical and Mathematical Methods for Predicting Behavior Nicholas Jon Stave Marquette University
    Marquette University e-Publications@Marquette Master's Theses (2009 -) Dissertations, Theses, and Professional Projects Analysis of BJT Colpitts Oscillators - Empirical and Mathematical Methods for Predicting Behavior Nicholas Jon Stave Marquette University Recommended Citation Stave, Nicholas Jon, "Analysis of BJT Colpitts sO cillators - Empirical and Mathematical Methods for Predicting Behavior" (2019). Master's Theses (2009 -). 554. https://epublications.marquette.edu/theses_open/554 ANALYSIS OF BJT COLPITTS OSCILLATORS – EMPIRICAL AND MATHEMATICAL METHODS FOR PREDICTING BEHAVIOR by Nicholas J. Stave, B.Sc. A Thesis submitted to the Faculty of the Graduate School, Marquette University, in Partial Fulfillment of the Requirements for the Degree of Master of Science Milwaukee, Wisconsin August 2019 ABSTRACT ANALYSIS OF BJT COLPITTS OSCILLATORS – EMPIRICAL AND MATHEMATICAL METHODS FOR PREDICTING BEHAVIOR Nicholas J. Stave, B.Sc. Marquette University, 2019 Oscillator circuits perform two fundamental roles in wireless communication – the local oscillator for frequency shifting and the voltage-controlled oscillator for modulation and detection. The Colpitts oscillator is a common topology used for these applications. Because the oscillator must function as a component of a larger system, the ability to predict and control its output characteristics is necessary. Textbooks treating the circuit often omit analysis of output voltage amplitude and output resistance and the literature on the topic often focuses on gigahertz-frequency chip-based applications. Without extensive component and parasitics information, it is often difficult to make simulation software predictions agree with experimental oscillator results. The oscillator studied in this thesis is the bipolar junction Colpitts oscillator in the common-base configuration and the analysis is primarily experimental. The characteristics considered are output voltage amplitude, output resistance, and sinusoidal purity of the waveform.
    [Show full text]
  • Oscillator Circuit Evaluation Method (2) Steps for Evaluating Oscillator Circuits (Oscillation Allowance and Drive Level)
    Technical Notes Oscillator Circuit Evaluation Method (2) Steps for evaluating oscillator circuits (oscillation allowance and drive level) Preface In general, a crystal unit needs to be matched with an oscillator circuit in order to obtain a stable oscillation. A poor match between crystal unit and oscillator circuit can produce a number of problems, including, insufficient device frequency stability, devices stop oscillating, and oscillation instability. When using a crystal unit in combination with a microcontroller, you have to evaluate the oscillator circuit. In order to check the match between the crystal unit and the oscillator circuit, you must, at least, evaluate (1) oscillation frequency (frequency matching), (2) oscillation allowance (negative resistance), and (3) drive level. The previous Technical Notes explained frequency matching. These Technical Notes describe the evaluation methods for oscillation allowance (negative resistance) and drive level. 1. Oscillation allowance (negative resistance) evaluations One process used as a means to easily evaluate the negative resistance characteristics and oscillation allowance of an oscillator circuits is the method of adding a resistor to the hot terminal of the crystal unit and observing whether it can oscillate (examining the negative resistance RN). The oscillator circuit capacity can be examined by changing the value of the added resistance (size of loss). The circuit diagram for measuring the negative resistance is shown in Fig. 1. The absolute value of the negative resistance is the value determined by summing up the added resistance r and the equivalent resistance (Re) when the crystal unit is under load. Formula (1) Rf Rd r | RN | Connect _ r＋R e ..
    [Show full text]
  • Lec#12: Sine Wave Oscillators
    Integrated Technical Education Cluster Banna - At AlAmeeria ‎ © Ahmad El J-601-1448 Electronic Principals Lecture #12 Sine wave oscillators Instructor: Dr. Ahmad El-Banna 2015 January Banna Agenda - © Ahmad El Introduction Feedback Oscillators Oscillators with RC Feedback Circuits 1448 Lec#12 , Jan, 2015 Oscillators with LC Feedback Circuits - 601 - J Crystal-Controlled Oscillators 2 INTRODUCTION 3 J-601-1448 , Lec#12 , Jan 2015 © Ahmad El-Banna Banna Introduction - • An oscillator is a circuit that produces a periodic waveform on its output with only the dc supply voltage as an input. © Ahmad El • The output voltage can be either sinusoidal or non sinusoidal, depending on the type of oscillator. • Two major classifications for oscillators are feedback oscillators and relaxation oscillators. o an oscillator converts electrical energy from the dc power supply to periodic waveforms. 1448 Lec#12 , Jan, 2015 - 601 - J 4 FEEDBACK OSCILLATORS FEEDBACK 5 J-601-1448 , Lec#12 , Jan 2015 © Ahmad El-Banna Banna Positive feedback - • Positive feedback is characterized by the condition wherein a portion of the output voltage of an amplifier is fed © Ahmad El back to the input with no net phase shift, resulting in a reinforcement of the output signal. Basic elements of a feedback oscillator. 1448 Lec#12 , Jan, 2015 - 601 - J 6 Banna Conditions for Oscillation - • Two conditions: © Ahmad El 1. The phase shift around the feedback loop must be effectively 0°. 2. The voltage gain, Acl around the closed feedback loop (loop gain) must equal 1 (unity). 1448 Lec#12 , Jan, 2015 - 601 - J 7 Banna Start-Up Conditions - • For oscillation to begin, the voltage gain around the positive feedback loop must be greater than 1 so that the amplitude of the output can build up to a desired level.
    [Show full text]
  • Hydraulics Manual Glossary G - 3
    Glossary G - 1 GLOSSARY OF HIGHWAY-RELATED DRAINAGE TERMS (Reprinted from the 1999 edition of the American Association of State Highway and Transportation Officials Model Drainage Manual) G.1 Introduction This Glossary is divided into three parts: · Introduction, · Glossary, and · References. It is not intended that all the terms in this Glossary be rigorously accurate or complete. Realistically, this is impossible. Depending on the circumstance, a particular term may have several meanings; this can never change. The primary purpose of this Glossary is to define the terms found in the Highway Drainage Guidelines and Model Drainage Manual in a manner that makes them easier to interpret and understand. A lesser purpose is to provide a compendium of terms that will be useful for both the novice as well as the more experienced hydraulics engineer. This Glossary may also help those who are unfamiliar with highway drainage design to become more understanding and appreciative of this complex science as well as facilitate communication between the highway hydraulics engineer and others. Where readily available, the source of a definition has been referenced. For clarity or format purposes, cited definitions may have some additional verbiage contained in double brackets [ ]. Conversely, three “dots” (...) are used to indicate where some parts of a cited definition were eliminated. Also, as might be expected, different sources were found to use different hyphenation and terminology practices for the same words. Insignificant changes in this regard were made to some cited references and elsewhere to gain uniformity for the terms contained in this Glossary: as an example, “groundwater” vice “ground-water” or “ground water,” and “cross section area” vice “cross-sectional area.” Cited definitions were taken primarily from two sources: W.B.
    [Show full text]
  • Oscillator Circuits
    Oscillator Circuits 1 II. Oscillator Operation For self-sustaining oscillations: • the feedback signal must positive • the overall gain must be equal to one (unity gain) 2 If the feedback signal is not positive or the gain is less than one, then the oscillations will dampen out. If the overall gain is greater than one, then the oscillator will eventually saturate. 3 Types of Oscillator Circuits A. Phase-Shift Oscillator B. Wien Bridge Oscillator C. Tuned Oscillator Circuits D. Crystal Oscillators E. Unijunction Oscillator 4 A. Phase-Shift Oscillator 1 Frequency of the oscillator: f0 = (the frequency where the phase shift is 180º) 2πRC 6 Feedback gain β = 1/[1 – 5α2 –j (6α – α3) ] where α = 1/(2πfRC) Feedback gain at the frequency of the oscillator β = 1 / 29 The amplifier must supply enough gain to compensate for losses. The overall gain must be unity. Thus the gain of the amplifier stage must be greater than 1/β, i.e. A > 29 The RC networks provide the necessary phase shift for a positive feedback. They also determine the frequency of oscillation. 5 Example of a Phase-Shift Oscillator FET Phase-Shift Oscillator 6 Example 1 7 BJT Phase-Shift Oscillator R′ = R − hie RC R h fe > 23 + 29 + 4 R RC 8 Phase-shift oscillator using op-amp 9 B. Wien Bridge Oscillator Vi Vd −Vb Z2 R4 1 1 β = = = − = − R3 R1 C2 V V Z + Z R + R Z R β = 0 ⇒ = + o a 1 2 3 4 1 + 1 3 + 1 R4 R2 C1 Z2 R4 Z2 Z1 , i.e., should have zero phase at the oscillation frequency When R1 = R2 = R and C1 = C2 = C then Z + Z Z 1 2 2 1 R 1 f = , and 3 ≥ 2 So frequency of oscillation is f = 0 0 2πRC R4 2π ()R1C1R2C2 10 Example 2 Calculate the resonant frequency of the Wien bridge oscillator shown above 1 1 f0 = = = 3120.7 Hz 2πRC 2 π(51×103 )(1×10−9 ) 11 C.
    [Show full text]
  • A 20 Mv Colpitts Oscillator Powered by a Thermoelectric Generator
    A 20 mV Colpitts Oscillator powered by a thermoelectric generator Fernando Rangel de Sousa∗, Marcio Bender Machado∗†, Carlos Galup-Montoro ∗ ∗Integrated Circuits Laboratory-LCI Federal University of Santa Catarina-UFSC Florianopolis-SC, Brazil, Tel.: +55-48-3721-7640 Email:[email protected] † Sul-Rio-Grandense Federal Institute Charqueadas-RS, Brazil Email:[email protected] Abstract—In this paper, we present a MOSFET-based Colpitts of around 13 mV , only seven milivolts far from the voltage oscillator based on a “zero-threshold” transistor operating at a supply value for which the circuit sustained oscillations at 130 supply voltage below 20 mV. The circuit was carefully analyzed mV(peak-to-peak)/97 kHz. Moreover, the circuit was powered and expressions relating the start-up conditions and the voltage supply, as well as the oscillation frequency were developed. by a thermoelectric generator which supplied a DC voltage of Measurement results obtained on a discrete prototype confirmed around 22 mV when it was installed on the arm of a person the low-voltage operation of the oscillator, which sustained in a 24oC room. oscillations of 130 mV (peak-to-peak) at 97 kHz when the voltage supply was 19.8 mV. The circuit was also powered from a II. COLPITTS OSCILLATOR thermoelectric generator (TEG) connected to a persons arm in a room with temperature of 24oC room. Under these conditions, A Colpitts oscillator can be broken in two main blocks : i) the TEG supplied 22 mV and the circuit operated as expected. a potentially unstable one-port and ii) a load network, as it is shown in Fig.
    [Show full text]
  • A Study of Phase Noise in Colpitts and LC-Tank CMOS Oscillators
    Downloaded from orbit.dtu.dk on: Oct 02, 2021 A study of phase noise in colpitts and LC-tank CMOS oscillators Andreani, Pietro; Wang, Xiaoyan; Vandi, Luca; Fard, A. Published in: I E E E Journal of Solid State Circuits Link to article, DOI: 10.1109/JSSC.2005.845991 Publication date: 2005 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Andreani, P., Wang, X., Vandi, L., & Fard, A. (2005). A study of phase noise in colpitts and LC-tank CMOS oscillators. I E E E Journal of Solid State Circuits, 40(5), 1107-1118. https://doi.org/10.1109/JSSC.2005.845991 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 40, NO. 5, MAY 2005 1107 A Study of Phase Noise in Colpitts and LC-Tank CMOS Oscillators Pietro Andreani, Member, IEEE, Xiaoyan Wang, Luca Vandi, and Ali Fard Abstract—This paper presents a study of phase noise in CMOS phase noise itself.
    [Show full text]
  • Oscillations
    CHAPTER FOURTEEN OSCILLATIONS 14.1 INTRODUCTION In our daily life we come across various kinds of motions. You have already learnt about some of them, e.g., rectilinear 14.1 Introduction motion and motion of a projectile. Both these motions are 14.2 Periodic and oscillatory non-repetitive. We have also learnt about uniform circular motions motion and orbital motion of planets in the solar system. In 14.3 Simple harmonic motion these cases, the motion is repeated after a certain interval of 14.4 Simple harmonic motion time, that is, it is periodic. In your childhood, you must have and uniform circular enjoyed rocking in a cradle or swinging on a swing. Both motion these motions are repetitive in nature but different from the 14.5 Velocity and acceleration periodic motion of a planet. Here, the object moves to and fro in simple harmonic motion about a mean position. The pendulum of a wall clock executes 14.6 Force law for simple a similar motion. Examples of such periodic to and fro harmonic motion motion abound: a boat tossing up and down in a river, the 14.7 Energy in simple harmonic piston in a steam engine going back and forth, etc. Such a motion motion is termed as oscillatory motion. In this chapter we 14.8 Some systems executing study this motion. simple harmonic motion The study of oscillatory motion is basic to physics; its 14.9 Damped simple harmonic motion concepts are required for the understanding of many physical 14.10 Forced oscillations and phenomena. In musical instruments, like the sitar, the guitar resonance or the violin, we come across vibrating strings that produce pleasing sounds.
    [Show full text]
  • Oscilators Simplified
    SIMPLIFIED WITH 61 PROJECTS DELTON T. HORN SIMPLIFIED WITH 61 PROJECTS DELTON T. HORN TAB BOOKS Inc. Blue Ridge Summit. PA 172 14 FIRST EDITION FIRST PRINTING Copyright O 1987 by TAB BOOKS Inc. Printed in the United States of America Reproduction or publication of the content in any manner, without express permission of the publisher, is prohibited. No liability is assumed with respect to the use of the information herein. Library of Cangress Cataloging in Publication Data Horn, Delton T. Oscillators simplified, wtth 61 projects. Includes index. 1. Oscillators, Electric. 2, Electronic circuits. I. Title. TK7872.07H67 1987 621.381 5'33 87-13882 ISBN 0-8306-03751 ISBN 0-830628754 (pbk.) Questions regarding the content of this book should be addressed to: Reader Inquiry Branch Editorial Department TAB BOOKS Inc. P.O. Box 40 Blue Ridge Summit, PA 17214 Contents Introduction vii List of Projects viii 1 Oscillators and Signal Generators 1 What Is an Oscillator? - Waveforms - Signal Generators - Relaxatton Oscillators-Feedback Oscillators-Resonance- Applications--Test Equipment 2 Sine Wave Oscillators 32 LC Parallel Resonant Tanks-The Hartfey Oscillator-The Coipltts Oscillator-The Armstrong Oscillator-The TITO Oscillator-The Crystal Oscillator 3 Other Transistor-Based Signal Generators 62 Triangle Wave Generators-Rectangle Wave Generators- Sawtooth Wave Generators-Unusual Waveform Generators 4 UJTS 81 How a UJT Works-The Basic UJT Relaxation Oscillator-Typical Design Exampl&wtooth Wave Generators-Unusual Wave- form Generator 5 Op Amp Circuits
    [Show full text]
  • The Harmonic Oscillator
    Appendix A The Harmonic Oscillator Properties of the harmonic oscillator arise so often throughout this book that it seemed best to treat the mathematics involved in a separate Appendix. A.1 Simple Harmonic Oscillator The harmonic oscillator equation dates to the time of Newton and Hooke. It follows by combining Newton’s Law of motion (F = Ma, where F is the force on a mass M and a is its acceleration) and Hooke’s Law (which states that the restoring force from a compressed or extended spring is proportional to the displacement from equilibrium and in the opposite direction: thus, FSpring =−Kx, where K is the spring constant) (Fig. A.1). Taking x = 0 as the equilibrium position and letting the force from the spring act on the mass: d2x M + Kx = 0. (A.1) dt2 2 = Dividing by the mass and defining ω0 K/M, the equation becomes d2x + ω2x = 0. (A.2) dt2 0 As may be seen by direct substitution, this equation has simple solutions of the form x = x0 sin ω0t or x0 = cos ω0t, (A.3) The original version of this chapter was revised: Pages 329, 330, 335, and 347 were corrected. The correction to this chapter is available at https://doi.org/10.1007/978-3-319-92796-1_8 © Springer Nature Switzerland AG 2018 329 W. R. Bennett, Jr., The Science of Musical Sound, https://doi.org/10.1007/978-3-319-92796-1 330 A The Harmonic Oscillator Fig. A.1 Frictionless harmonic oscillator showing the spring in compressed and extended positions where t is the time and x0 is the maximum amplitude of the oscillation.
    [Show full text]
  • Forced Oscillation and Resonance
    Chapter 2 Forced Oscillation and Resonance The forced oscillation problem will be crucial to our understanding of wave phenomena. Complex exponentials are even more useful for the discussion of damping and forced oscil- lations. They will help us to discuss forced oscillations without getting lost in algebra. Preview In this chapter, we apply the tools of complex exponentials and time translation invariance to deal with damped oscillation and the important physical phenomenon of resonance in single oscillators. 1. We set up and solve (using complex exponentials) the equation of motion for a damped harmonic oscillator in the overdamped, underdamped and critically damped regions. 2. We set up the equation of motion for the damped and forced harmonic oscillator. 3. We study the solution, which exhibits a resonance when the forcing frequency equals the free oscillation frequency of the corresponding undamped oscillator. 4. We study in detail a specific system of a mass on a spring in a viscous fluid. We give a physical explanation of the phase relation between the forcing term and the damping. 2.1 Damped Oscillators Consider first the free oscillation of a damped oscillator. This could be, for example, a system of a block attached to a spring, like that shown in figure 1.1, but with the whole system immersed in a viscous fluid. Then in addition to the restoring force from the spring, the block 37 38 CHAPTER 2. FORCED OSCILLATION AND RESONANCE experiences a frictional force. For small velocities, the frictional force can be taken to have the form ¡ m¡v ; (2.1) where ¡ is a constant.
    [Show full text]