解 i,=ls0-ag RF信号充分小， 忽略 g(t)= 2+3 dvcs (VV) GS(off 1 10×10-3 8c= 81 Ipss Vim= ×0.4=1mS 2 Vasu) 4 Rp= =142.6k2 0,C 变频增益： Avc goRp =142解: 2 ( ) (1 ) GS D DSS GS off V i I V = − ( ) 2 ( ) 2 2 ( ) ( cos ) GS off D DSS DSS GSQ Lm L GS GS off di I I g t V V t dv V V = = − + − ω RF信号充分小， 忽略 3 1 2 ( ) 1 10 10 0.4 1 2 4 DSS c Lm GS off I g g V mS V − × = = = × = 142.6 L P I Q R k ω C = = Ω 142 变频增益： A g vc = cRP =