公开(公告)号：US09882588B2

公开(公告)日：2018-01-30

申请号：US15138365

申请日：2016-04-26

Applicant: MediaTek Inc.

Inventor： Keng Leong Fong ,  Wei-Kai Hong ,  Ming Chung Liu

IPC: H04B1/04 ,  H03F1/02 ,  H03F1/56 ,  H03F3/189 ,  H03F1/08 ,  H03F3/195 ,  H03F3/21 ,  H03F3/213 ,  H03F3/45

CPC classification number: H04B1/0458 ,  H03F1/0277 ,  H03F1/08 ,  H03F1/56 ,  H03F3/189 ,  H03F3/195 ,  H03F3/211 ,  H03F3/213 ,  H03F3/45071 ,  H03F2200/387 ,  H03F2200/451 ,  H03F2200/541 ,  H03F2203/21139 ,  H03F2203/45228

Abstract: An amplifier circuit that includes a first power amplifier configured to drive a load and a second power amplifier configured to drive the load through an impedance step-up network. The impedance step-up network is connected to an output of the second power amplifier. The impedance step-up network is configured to switch into a first mode to present an increased impedance to the first power amplifier, and switch into a second mode in which the impedance step-up network steps-up an impedance seen by the second power amplifier looking into the impedance step-up network.