05通信信号与系统B A卷 答案

3)由系统的s域模型得U(s)?U(s)?F(s)?2iL(0?)2s?1(2?2s)F(s)(2s?1)(s?2)2?2F(s)?uc(0?)s?2(s?2)2iL(0?)?uc(0?)(2s?1)(2s?1)(s?2)?(s?2)2iL(0?)?uc(0?)(2s?1)Ux(s)?(2s?1)(s?2)iL(0?)?1Auc(0?)?1V?U4s?5x(s)?(2s?1)(s?2)?11s?1?2s?2?u(t)?e?12tx?e?2t,t?0U2(1?s2)f(s)?(s?12)(s?2)s?2s?2s?1-2s?22?u(t)?2(1?e?12t?e?2tf),t?0u(t)?ux(t)?uf(t)?1?2?e2t?e?2t,t?0第9页共9页