Engineering Circuit Analysis: International Student Version, Tenth Edition

Chapter 12. VARIABLE-FREQUENCY NETWORK PERFORMANCE

THE LEARNING GOALS FOR THIS CHAPTER ARE:

• Understand the variable-frequency performance of the basic circuit elements: R, L, and C

• Learn the different types of network functions and the definition of poles and zeros

• Be able to sketch a Bode plot for a network function

• Know how to create a Bode plot

• Know how to analyze series and parallel resonant circuits

• Be introduced to the concepts of magnitude and frequency scaling

• Learn the characteristics of basic filters such low-pass, high-pass, band-pass, and band rejection

• Know how to analyze basic passive and active filters

Music and Frequency Time and frequency are two sides of the same coin, describing signals in two ways. We hear music, for example, as a time signal but the sampling rate for its digital recording, mastering, and manufacturing depends on signal bandwidth—a frequency description. We utilize both "languages"—time and frequency—to design recording and playback equipment. For iPods and MP3 players on laptops, the bandwidth has to be large enough to reproduce music in frequency ranges from bass to violin and from tuba to flute. For reference, concert flutes have frequencies from 262 Hz to over 2 kHz (middle C to three octaves above).

Your hearing must have a bandwidth that extends to frequencies at least as high as the highest frequency present in the musical signal. Voice or other signals ...