Analysis and design of power and efficiency in third-order matching networks for switched-capacitor power-amplifiers

This paper presents the design of a matching network (MN) for switched-capacitor PAs (SCPA) optimized for efficiency against required load output power. The presented third-order MN exploits the intrinsic output capacitance of the SCPA, reducing the number of passive components required by the MN. As an example, a MN for a 1.1 V switched capacitor power amplifier has been designed with a bluetooth application in mind. The example MN has been implemented in a 28 nm CMOS RF metal stack and provides 16.7 dBm output power with IL = 1.1 dB at 2.4 GHz in an area of 300 x 300 um^2 when resonated by an SCPA capacitance of 2.3 pF. Further structures have then been implemented and characterized, covering a broader set of applications.