Page 470 - Engineering Electromagnetics, 8th Edition

452 ENGINEERING ELECTROMAGNETICS

determine the wavelength-dependent (or independent) group delay over a
unit distance. (c) Determine β 2 from your result of part (b). (d) Discuss the
implications of these results, if any, on pulse broadening.
12.29 A T = 5ps transform-limited pulse propagates in a dispersive medium for
2
which β 2 = 10 ps /km. Over what distance will the pulse spread to twice its
initial width?
12.30 A T = 20 ps transform-limited pulse propagates through 10 km of a
2
dispersive medium for which β 2 = 12 ps /km. The pulse then propagates
2
through a second 10 km medium for which β 2 =−12 ps /km. Describe the
pulse at the output of the second medium and give a physical explanation
for what happened.