-P()1- .-Zo +Z。 Re(Z)≥0，Re(Zi)20 ZiZr+Zl maxP=P*1+k2=P≥P+( ) ÷ ÷ ø ö ç ç è æ + - = + - + 2 0 * 2 0 1 1 Z Z Z Z P P k L L L Z0 -Z0 Z0 * 0 * ZL - Z0 £ ZL + Z Re(Z0 ) ³ 0, Re(ZL ) ³ 0 ( ) + + PL = P + k = Pk ³ P 2 max 1