High-linearity variable gain amplifier with bypass path

A variable gain amplifier assembly having a signal input and a signal output, the variable gain amplifier assembly comprising:

• a variable gain amplifier including a plurality of unit cell groups, each unit cell group of the plurality of unit cell groups including at least one unit cell having at least one transistor, the variable gain amplifier configured to apply a different gain to a signal received at the signal input during each of a plurality of amplify modes, each of the plurality of amplify modes corresponding to at least one unit cell group of the plurality of unit cell groups;
• a controller configured to select an amplify mode of the plurality of amplify modes of the variable gain amplifier and provide a respective reference current value of a plurality of reference current values for each of the plurality of amplify modes based on at least an amplitude of the signal received at the signal input;
• and
• a current control circuit coupled to the controller and the variable gain amplifier and configured to regulate a bias current provided to the at least one transistor of the at least one unit cell based on the respective reference current value received from the controller.

A variable gain amplifier circuit, comprising:

• a differential signal input to receive an input signal;
• a differential signal output to provide an output signal;
• a variable gain amplifier configured to provide an adjustable gain to the input signal to generate an amplified signal as the output signal, the adjustable gain being based at least in part on a selected amplify mode of the variable gain amplifier;
• a first switching circuit positioned between the differential signal input and the variable gain amplifier, and a second switching circuit positioned between the differential signal output and the variable gain amplifier, the first switching circuit and the second switching circuit collectively configured to couple the variable gain amplifier between the differential signal input and the differential signal output during the selected amplify mode;
• and
• a bypass path positioned in parallel with the variable gain amplifier, the bypass path including a fixed attenuator, a third switching circuit, and a fourth switching circuit, the third switching circuit and the fourth switching circuit collectively configured to couple the differential signal input and the differential signal output through the fixed attenuator during a bypass mode.