公开(公告)号：WO2014078742A3

公开(公告)日：2014-07-03

申请号：PCT/US2013070434

申请日：2013-11-15

Applicant: QUALCOMM INC

Inventor： CHA JEONGWON ,  LEE CHANG-HO ,  HADJICHRISTOS ARISTOTELE

IPC: H03F1/02 ,  H03F1/22 ,  H03F1/52 ,  H03F3/21 ,  H03K17/10

CPC classification number: H03F1/0277 ,  H03F1/223 ,  H03F1/523 ,  H03F3/211 ,  H03F3/245 ,  H03F2200/61 ,  H03K17/102

Abstract: Techniques for providing adjustable gain in an amplifier. In an aspect, a composite amplifier having adjustable gain includes a plurality of amplifiers coupled in parallel, wherein each of the amplifiers may be turned on or off to adjust the overall gain of the composite amplifier. Each amplifier may include an input transistor and at least two cascode transistors. To turn each amplifier off, the gate voltage of a second or lowermost cascode transistor coupled to the input transistor may be grounded, and the gate voltage of a first cascode transistor coupled to the output voltage may be coupled to a first turn-off voltage to reduce the drain-to-gate voltage drop across the first cascode transistor. Further aspects provide for decoupling a capacitor coupled to the gates of the cascode transistors from AC ground when the amplifier is turned off.

Abstract translation: 在放大器中提供可调增益的技术。 在一方面，具有可调增益的复合放大器包括并联耦合的多个放大器，其中每个放大器可被导通或关断以调整复合放大器的总体增益。 每个放大器可以包括输入晶体管和至少两个共源共栅晶体管。 为了关闭每个放大器，耦合到输入晶体管的第二或最低共源共栅晶体管的栅极电压可以接地，并且耦合到输出电压的第一共源共栅晶体管的栅极电压可以耦合到第一截止电压到 降低跨越第一共源共栅晶体管的漏极 - 栅极电压降。 另外的方面提供了当放大器关闭时将耦合到共源共栅晶体管的栅极的电容器与AC地耦合的去耦合。