Patent ID: 7889005

Claim:
A controllable amplifier comprising: a first input configured to receive a radiofrequency input signal; a second input configured to receive an analog control signal for gain; an output; and a current path connected between a supply potential connection and a reference potential connection, wherein the current path comprises: an amplifier transistor having a first connection coupled to the reference potential connection, a second connection, and a control input coupled to the first input; a cascode transistor having a control input coupled to the second input, a first connection coupled to the second connection of the amplifier transistor, and a second connection coupled to the output, wherein the cascode transistor is configured to operate over a plurality of different, non-zero gains in an analog fashion based on the analog control signal provided at the control input thereof, wherein the analog control signal is operable to adjust the gain of the cascode transistor in the analog fashion; an auxiliary current path comprising a first auxiliary transistor, a second auxiliary transistor, an output, and a feedback path, wherein the first auxiliary transistor comprises a control input, the second auxiliary transistor comprises a control input, and the first auxiliary transistor and the second auxiliary transistor are connected in series; wherein the control input of the first auxiliary transistor is connected to the control input of the amplifier transistor; wherein the output of the auxiliary current path is connected to a first connection of the second auxiliary transistor; and wherein the feedback path of the auxiliary current path is connected to the output of the auxiliary current path and the second input.