An architecture and method for improving efficiency of a Class-A power amplifier by dynamically scaling biasing current thereof as well as synchronously compensating gain thereof in order to maintain overall constant gain of the Class-A power amplifier at all biasing configurations thereof. A biasing-current switching-network is operatively connected to the back-end block of the Class-A power amplifier. A gain-control switching-network is operatively connected to a front-end block of the Class-A power amplifier. A detector-and-control block is operatively connected to an output of the back-end block of the Class-A power amplifier, and samples a signal that is then compared with reference signals to determine switching configurations in the biasing-current switching-network and the gain-control switching network when the signal is processed through the front-end block of the Class-A power amplifier followed by the back-end block of the Class-A power amplifier. The biasing-current switching-network dynamically sets the back-end block biasing current of the Class-A power amplifier for a highest possible operating efficiency. The gain-control network simultaneously adjusts gain of the front-end block of the Class-A power amplifier to synchronize with a dynamic-biasing current-switching configuration to allow overall gain of the Class-A power amplifier to be constant in all biasing conditions.