)7.1调频信号和调相信号 △p(t)=k,4n p(t)=0t+△0 do(t) Wc o(t)= dt upy =Um cos(@ct+mp cosst+o) 调相信号波形uPM Usm cosC t  mP cost   0    d t t dt      C  t  t     P  t k u    7.1 调频信号和调相信号