1 / 31

EE 448

EE 448. University of Southern California Department of Electrical Engineering. Dr. Edward W. Maby Class #1 11 January 2005. Course Personnel. Dr. Edward W. Maby (Instructor) maby@usc.edu 740-4706 Office Hours: MW 1:00 - 2:00 PHE 626 Clint Colby ccolby@usc.edu Tyler Rather

Albert_Lan
Télécharger la présentation

EE 448

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EE 448 University of Southern California Department of Electrical Engineering Dr. Edward W. Maby Class #1 11 January 2005

  2. Course Personnel • Dr. Edward W. Maby (Instructor) • maby@usc.edu 740-4706 • Office Hours: MW 1:00 - 2:00 PHE 626 • Clint Colby • ccolby@usc.edu • Tyler Rather • rather@usc.edu

  3. Grading Policy • Midterm 1 25% 17 February • Midterm 2 25% 24 March • Homework 15% • Final Exam 35% 10 May • No Make-Up Exams • Homework Conditions Borderline Grades • Same “Curve” for Graduate Students

  4. Course Objectives • Circuit Concepts for RF Systems • Transmission Lines, Impedance Matching • Noise and Distortion Analysis • Filter Design • RF System Components • Low-Noise Amplifiers, Power Amplifiers • Mixers and Oscillators • Elementary Transmitter/Receiver Architectures and Their Board-Level Implementation

  5. Why RF ? • Ever-Growing Wireless Applications • Personal Communication Systems • Satellite Systems • Global Positioning Systems • Wireless Local-Area Networks • Strong Demand for Wireless Engineers • Digital is HOT • Analog is COOL • RF Design is an ART

  6. Emphasis ??? • Designing RF Integrated Circuits • Some Engineers • Designing With RF Integrated Circuits • More Engineers • Difficult to Satisfy Both Objectives

  7. EE 448 Textbooks • The Design of CMOS Radio-Frequency Integrated Circuits • Thomas H. Lee (required) • Planar Microwave Engineering: A Practical Guide to Theory Measurements and Circuits • Thomas H. Lee • Radio Frequency Circuit Design • W. Alan Davis and Krishna K. Agarwal • Advanced RF Engineering for Wireless Systems and Networks • Arshad Hussain • Microwave and RF Design of Wireless Systems • David M. Pozar • High-Frequency Techniques • Joseph F. White

  8. Some Good Advice … • Read the Syllabus • Come to Class (Come to Class Early) • Do the Homework (But Not One Hour Before a Deadline) (And Don’t Give Up Easily) • Enjoy the Course !

  9. Basic Radio Systems Data In Power Amplifier Bandpass Filter Modulator IF Filter Mixer X Transmitter Local Oscillator IF Amplifier Bandpass Filter Low-Noise Amplifier Demodulator IF Filter Mixer X Receiver Local Oscillator Data Out

  10. Connecting the Boxes • Antenna RF Link Between Transmitter and Receiver (Marginal Issue for EE 448) • Transmission-Line Connections Between Internal Transmitter/Receiver Components • l = Velocity / Frequency • Circuit Dimensions Comparable to l at High Frequencies (>> 1 GHz) • “Distributed” Circuit Behavior

  11. Transmission-Line Model • Two “Wires” with Uniform Cross Section • L (inductance), C (capacitance) per unit length • Transverse Electromagnetic Fields • Quasi-Static Solutions • L = L (m, xy geometry), C = C (e, xy geometry), • L C = me • R (resistance), G (conductance) per unit length (Consider Physical Mechanisms Later)

  12. Telegraphers Equations (Heaviside, 1880)

  13. Power Implications Change in Stored Linear Energy Density Dissipated Power

  14. Time-Domain Solutions (No Loss) Wave Equation Forward Wave Reverse Wave Velocity No Wave Dispersion (Corruption) During Propagation

  15. Frequency Domain v and i haveTime Dependence (Similar equation for i) Propagation Constant R and G may be w dependent

  16. Freq.-Domain Solutions Forward Reverse (V+ and V- are Fourier Amplitudes) Similar form for i (z,t); however, Characteristic Line Impedance (Zo Follows Directly from Transmission-Line Model)

  17. Low-Loss Propagation (OK to 10 GHz) Assume For Line Length l, • Attenuation in dB • Attenuation in nepers

  18. Velocities and Wavelength Fixed Phase Angle Phase Velocity: w Independent No Dispersion Group Velocity: (Applies to Modulated Signal) Wavelength:

  19. Historical Remarks (Transatlantic Cable) First Telegrapher’s Equations: (No L or G) Prof. William Thomson (Later Lord Kelvin) 1854 Diffusion Equation (Applies to Most Ordinary IC Interconnects)

  20. Diffusion Solutions Unit-Step Input: For line length l, imax at Pulse Input:

  21. Diffusion “Velocity” Sinusoidal Input: “Velocity” Dispersion, High-Frequency Attenuation

  22. Did Engineers Care? Dr. Edward Orange Wildman Whitehouse M.D. Chief Electrician, Atlantic Telegraph Company, 1856 On Thomson’s Results … “In all honesty, I am bound to answer, that I believe nature knows no such application of that law; and I can only regard it as a fiction of the schools, a forced and violent adaptation of a principle in Physics, good and true under other circum- stances, but misapplied here.” Nahin, p. 34 First Transatlantic Cable (1858) Whitehouse: Long Cable Requires Large-Voltage Input 2000-V “Stroke of Lightning” per Pulse (Obviously)

  23. What Happened Next? • Queen Victoria and James Buchanan Exchange Messages • Great Celebration, Public Pleased • Cable Insulation Fails, Cable Dead, Public Angry • Boston Headline: Was the Atlantic Cable a Humbug? • Investor: Was Cyrus Field an Inside Trader? • Further Experiments: High Voltage Not Necessary • Whitehouse Fired • Second Transatlantic Cable Successful (1866)

  24. Minimal Dispersion ? Telegraph Lines Make Poor Telephone Lines (Bell Fails to Propagate Voice Over Atlantic Cable - 1877) ? Heaviside (1887) Increase L by Adding Series Loading Coils at l/4 Intervals Improve Audio Bandwidth, But Suppress High Frequencies H88 Standard (88 mH at 6000-foot Intervals) Bad for DSL

  25. Dispersion - Skin Effect Skin Depth Real Part: Amplitude Distortion Imaginary Part: Phase Distortion Rise Time

  26. Dispersion - Dielectric Loss General Relation for Capacitance: Dielectric Constant Has Real and Imaginary Parts (Loss Tangent) Loss Dielectric Loss Overtakes Skin-Depth Loss (f >> 1 GHz)

  27. Digital Digression • Dispersion Promotes Inter-Symbol Interference • Equalization at Receiver • Correct for Group Delay • Correct for Amplitude Distortion • Difficult for Very-High Data Rates • Pre-Emphasis (Pre-Distortion) at Transmitter • Increase Pulse Amplitude After Transition • MAX3292 (for RS-485) • See Widmer et al. (IBM) IEEE JSSC 31, 2004 (1996)

  28. Why 50 Ohms? (Lee, pp. 229-231) Consider Coaxial Cable With Inner and Outer Diameters a and b Maximum Deliverable Power: Zo = 30 W Minimum Attenuation: Zo = 77 W (75 W - Cable TV) Compromise: Zo = 50 W

  29. Microstrip Lines w e Substrate h • Important Substrate Properties • Relative Dielectric Constant • Loss Tangent • Thermal Conductivity • Dielectric Strength • Numerous Design Equations for Zo and Effective e • See Davis and Agarwal, pp. 71-74; Chang, pp. 43-49 • Calculator: http://mcalc.sourceforge.net/#calc

  30. Design Formulas • Define • Then • Assumes “Narrow” Lines

  31. References (Other than course texts) • Richard B. Adler, Lan Jen Chu, and Robert M. Fano, Electromagnetic Energy Transmission and Radiation (1960) • Paul J. Nahin, Oliver Heaviside: The Life, Work, and Times of an Electrical Genius of the Victorian Age (1988) • Henry M. Field, History of the Atlantic Telegraph (1866) • Kai Chang, RF and Microwave Wireless Systems (2000) • Richard E. Matick, Transmission Lines for Digital and Communication Networks (1969)

More Related