Amplifier and related method

A method for operating an amplifier applicable to an intra-band non-contiguous carrier aggregation (NCCA) band, the NCCA band including at least a primary component carrier (PCC) channel and a secondary component carrier (SCC) channel not adjacent to each other, the method comprising:

• utilizing a first amplifier circuit to receive a first input signal and generate a first output signal for undergoing down-conversion of one of the PCC channel and the SCC channel;
• providing at least one second input signal to a second amplifier circuit;
• and
• utilizing the second amplifier circuit to receive the at least one second input signal and to generate a second output signal for undergoing down-conversion of another of the PCC channel and the SCC channel;
• wherein the at least one second input signal received by the second amplifier circuit is provided by the first amplifier circuit according to the first input signal.