US 11,984,856 B2
Low noise amplifier and operation method of low noise amplifier
Gyu-Suck Kim, Suwon-si (KR); and Youngsik Hur, Suwon-si (KR)
Assigned to Samsung Electro-Mechanics Co., Ltd., Suwon-si (KR)
Filed by SAMSUNG ELECTRO-MECHANICS CO., LTD., Suwon-si (KR)
Filed on Jun. 28, 2021, as Appl. No. 17/360,794.
Claims priority of application No. 10-2020-0182450 (KR), filed on Dec. 23, 2020.
Prior Publication US 2022/0200537 A1, Jun. 23, 2022
Int. Cl. H03F 1/22 (2006.01); H03F 1/26 (2006.01)
CPC H03F 1/223 (2013.01) [H03F 1/26 (2013.01); H03F 2200/294 (2013.01); H03F 2200/318 (2013.01); H03F 2200/451 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A low noise amplifier, comprising:
an amplification unit including a first transistor and a second transistor connected in a cascode structure and configured to amplify a signal input to a control terminal of the first transistor; and
a gain controller connected between a contact point at which the first transistor and the second transistor are connected to each other and a power source voltage, and configured to adjust a gain of the amplification unit,
wherein the gain controller comprises a third transistor connected between the contact point and the power source voltage,
wherein a gain control voltage to adjust the gain of the amplification unit is applied to a control terminal of the third transistor, and
wherein the gain control voltage is configured to have a first voltage, a second voltage, and a third voltage for each of a first gain mode, a second gain mode, and a third gain mode.