Page 290 - Schaum's Outline of Theory and Problems of Signals and Systems
P. 290

CHAP. 51         FOURIER ANALYSIS OF TIME SIGNALS AND SYSTEMS



























                                                  Fig. 5-33


                 and






                 which indicates the inverse relationship between bandwidth and risetime.

           5.57.  Another definition of bandwidth for a signal x(t) is the 90 percent energy containment
                 bandwidth  W,,  defined by





                where  Ex  is  the  normalized  energy  content  of  signal  x(t). Find  the  W,  for  the
                following signals:
                (a)  x(t) = e-"'u(t), a > 0
                            sin at
                (b)  x(t)  = -
                              rr l
                (a)  From Eq. (5.155)
                                                                        1
                                            ~(t) e-"u(t) - X( W) = -
                                                 =
                                                                      a +jo
                     From Eq. (1.14)




                     Now, by  Eq. (5.180)
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