7+7-72=02=±+虚部为零与负实轴相交于 K G(o G-70)+)0+m 72(7+73)0=m1-72(+) 727 K q() 1-71T2O G(0+)=k-j0G(∞)=-0+j0 画出一半利用对称性画出另一半 1-2(+7)-1闭+2+1>K+17=12=27=3K=2 71T 727173 7=1,72=2,73=3,K=8 4 Real Axis 154154 0 2 T2 +T3 −T1T2T3 = 1 2 3 2 3 T T T T T c +  =  虚部为零与负实轴相交于 2 1 3 2 3 2 1 3 2 2 1 3 1 ( ) 1 ( ) ( ) T T T T T T T T K T T T K G j c c + − + = − + = =   ( ) 2 3 2 2 2 2 1 2 [(1 ) ( ) ][1 ( ) ] ( )       j e T T T T K G j − + + =      3 2 1 2 2 1 ( ) arctgT T T T arctg − − = − G( j0+) = K − j0 G( j) = −0 + j0 画出一半利用对称性画出另一半。 1 1 ( ) 2 1 3 2 3 2 1 3  − + − + T T T T T T T T K ( ) 1 1 3 2 3 1 3  + + + K T T T T T T T1 =1,T2 = 2,T3 = 3,K = 2 T1 =1,T2 = 2,T3 = 3,K = 8 -2 -1 0 1 2 3 4 5 6 7 8 -6 -4 -2 0 2 4 6 Real Axis Imag Axis