Patent ID: 7944296
Filing Date: 2011-05-17
Classification: H03F

Abstract:
1. A power amplifier system, comprising: a high-power amplifier; a transformer having a primary winding inductively coupled to a secondary winding, wherein the primary winding includes a first end or port, a second end or port, and a center tap between the first end or port and the second end or port, wherein the secondary winding includes a third end or port and a fourth end or port, wherein respective outputs of the high-power amplifier are connected to the first end or port and the second end or port of the primary winding; a first capacitor connected to the center tap and the first end or port of the primary winding; a second capacitor connected to the center tap and the second end or port of the primary winding; a low-power amplifier, wherein an output of the low-power amplifier is connected to the center tap port of the primary winding; a first switch connected to the center tap via a capacitive coupling element, wherein the first switch is operative to connect the center tap of the primary winding to a ground port; a second switch connected to the fourth end or port of the secondary winding, wherein the second switch is operative to connect the fourth end or port to a common node, the common node connected to the center tap of the primary winding via the capacitive coupling element; and a third capacitor connected between the common node and an output node connected to the third end or port of the secondary winding, wherein a system output is obtained from the output node.