Design of a wideband 1.5GHz to 3GHz class EF2 power amplifier

A class EF2 power amplifier with 32.7dB power gain is presented. To the authors´ knowledge, this class has never been presented in PA design in RF frequency. The class EF2 power amplifier presents lower voltage stress than its class E counterpart due to waveform engineering. The presented circuit was designed in standard ST Microelectronics CMOS 130nm and is able to deliver 20dBm RF output power from a 2V supply voltage with 55% drain efficiency and 49.8% PAE at 2.5GHz. The output power spectrum presents 34.7dB power difference between the fundamental frequency and the strongest upper harmonic. The circuit is able to work from 1.5GHz up to 3.0GHz if the 3dB power criterion is observed. A 500MHz bandwidth around 2.35GHz was achieved in which the performances stay fairly constant: output power varies only 0.6dB and PAE varies 2.5%. Both 1dB output power bandwidth and -3% PAE bandwidth is found to be around 28.2%. The total used area is 1660um × 1470um.