US 11,942,912 B2
Amplifier with tunable impedance circuit
Weiheng Chang, Thousand Oaks, CA (US)
Assigned to Skyworks Solutions, Inc., Irvine, CA (US)
Filed by SKYWORKS SOLUTIONS, INC., Irvine, CA (US)
Filed on Sep. 17, 2020, as Appl. No. 17/024,634.
Claims priority of provisional application 62/902,303, filed on Sep. 18, 2019.
Prior Publication US 2021/0083636 A1, Mar. 18, 2021
Int. Cl. H03F 3/72 (2006.01); H03F 1/56 (2006.01); H03F 3/195 (2006.01); H03F 3/24 (2006.01)
CPC H03F 3/72 (2013.01) [H03F 1/565 (2013.01); H03F 3/195 (2013.01); H03F 3/245 (2013.01); H03F 2200/294 (2013.01); H03F 2200/451 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A variable-gain amplifier comprising:
a gain circuit configured to amplify a signal, the gain circuit including a first transistor having a gate or a base coupled to an input node, the gain circuit being configured to selectively operate in a first gain mode based on a first amount of supply voltage and a second gain mode based on a second amount of supply voltage, the first transistor being implemented to amplify the signal in both the first gain mode and the second gain mode; and
an impedance circuit coupled to the first transistor at a single connection that is the gate or the base of the first transistor, the impedance circuit including an inductor and a switching-capacitive arm coupled in parallel to the inductor, the switching-capacitive arm including a capacitor and a switch coupled in series, the impedance circuit being configurable to (i) a first state, for the first gain mode, that includes the switch in an open state and the inductor connected in series with the input node and the gate or the base of the first transistor, and (ii) a second state, for the second gain mode, that includes the switch in a closed state and the inductor and the capacitor connected with the input node and the gate or the base of the first transistor.