◇第4正弦波振荡器 U(S)=K(SU(SF(S) U/(s)U(s)=U(( Uo(s) K(S) U。(s)K(s)1(s) U(s)U1(s)-U/(s) K(S K(s) K(S F(s)U0(s)1-K(s)F(s)1-T(s) (4-5) 7(S)=K(s)F(S) U/;(s) U(sT(S)-反馈系统的环路增益(46)第4章 正弦波振荡器 1 ( ) ( ) 1 ( ) ( ) ( ) ( ) ( ) ( ) 1 ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) i o i i i s o u T s K s K s F s K s U s F s U s K s U s U s K s U s U s U s K s − = − = − = −  = = ( ) ( ) ( ) ( ) ( ) i i U s U s T s K s F s  = = ( ) ( ) ( ) o i U s = K s U s ( ) ( ) ( ) o i U s U s F s  = ( ) ( ) ( ) s i i U s =U s −U s T(S)---反馈系统的环路增益 (4-5) (4-6)