阅读说明：本技术 一种可变增益放大器 (Variable gain amplifier ) 是由 李天一 于 2019-02-27 设计创作，主要内容包括：一种可变增益放大器VGA,第一共源管对分别与第一共栅管对和第二共栅管对构成共源共栅结构,第二共源管对分别与第三共栅管对和第四共栅管对构成共源共栅结构,第一负载电阻分别耦合第一共栅管对中一个共栅管的漏极和第三共栅管对中一个共栅管的漏极,第二负载电阻分别耦合第一共栅管对中另一个共栅管的漏极和第三共栅管对中另一个共栅管的漏极,第一虚拟电阻分别耦合第二虚拟电阻、第二共栅管对中两个共栅管的漏极和第四共栅管对中两个共栅管的漏极,分流电路分别耦合第一共栅管对中两个共栅管的源极和第一虚拟电阻,反向并联电路分别耦合第三共栅管对中两个共栅管的源极、第一负载电阻和第二负载电阻。本申请实施例,可以提高VGA的性能。(The invention discloses a variable gain amplifier VGA. A first common source tube pair forms a common source and common gate structure respectively with a first common gate tube pair and a second common gate tube pair, the second common source tube pair forms a common source and common gate structure respectively with a third common gate tube pair and a fourth common gate tube pair, a first load resistor is respectively coupled with a drain electrode of one common gate tube in the first common gate tube pair and a drain electrode of one common gate tube in the third common gate tube pair, a second load resistor is respectively coupled with a drain electrode of the other common gate tube in the first common gate tube pair and a drain electrode of the other common gate tube in the third common gate tube pair, a first virtual resistor is respectively coupled with a second virtual resistor, drain electrodes of two common gate tubes in the second common gate tube pair and drain electrodes of two common gate tubes in the fourth common gate tube pair, a shunt circuit is respectively coupled with source electrodes of two common gate tubes in the first common gate tube pair and the first virtual resistor, and an anti-parallel circuit is respectively coupled with source electrodes of two common gate tubes in the third common gate tube pair, the first load resistor and the second load resistor. According to the embodiment of the invention, the performance of the VGA can be improved.)