Low noise amplifiers with low noise figure

A mobile device comprising:

• an antenna configured to provide a single-ended input signal in response to receiving a radio wave;
• and
• a front-end system including a single-ended cascode field-effect transistor stage configured to amplify the single-ended input signal to generate a single-ended amplified signal, an input balun having a first winding configured to receive the single-ended amplified signal and a second winding configured to output a differential amplified signal, and a first differential low noise amplifier stage configured to receive the differential amplified signal in a first mode, the single-ended cascode field-effect transistor stage including a first input stage series inductor, an input stage series capacitor, an input stage gain field-effect transistor having a gate that receives the single-ended input signal through the first input stage series inductor and the input stage series capacitor, a second input stage series inductor, and an input stage cascode field-effect transistor having a source connected to a drain of the input stage gain field-effect transistor through the second input stage series inductor.