This paper proposes a new technique and design methodology on a transformer-based Class-E complementary metal-oxide-semiconductor (CMOS) power amplifier (PA) with only one transformer and two capacitors in the load network. An analysis of this amplifier is presented together with an accurate and simple design procedure. The experimental results are in good agreement with the theoretical analysis. The following performance parameters are determined for optimum operation: The current and voltage waveform, the peak value of drain current and drain-to-source voltage, the output power, the efficiency and the component values of the load network are determined to be essential for optimum operation. The measured drain efficiency (DE) and power-added efficiency (PAE) is over 70% with 10-dBm output power at 2.4 GHz, using a 65 nm CMOS process technology.
A Design Methodology and Analysis for Transformer-Based Class-E Power Amplifier