A broadband power combining method comprises the steps of converting desired voltage or current relation over a specified frequency band to specified polynomial transfer equation; steps of formulating the said specified polynomial transfer equation and extracting the coefficients of the denominator polynomial functions; steps of comparing the said voltage/current transfer function in first step with the design goal to decide if the design criteria is met; and a multiple-device power combining amplifier using same method is presented. This invention presents an automated method for the designing high power multiple-device amplifier based on a compact, robust and easily extendable combining circuit-synthesis method. By using multiple low-power transistors and the proposed circuit synthesis method, this broadband power combining amplifier can provide high power level with 100% power combining efficiency over any given wide bandwidth, thereby allowing for high-speed communication with less power consumption at lower cost when used in cellular or satellite transceiver systems.