Towards greener wireless transmission: Efficient power amplifier design

The power budget of a transmitter is critically dependent on the design of the Power Amplifier (PA). Different applications require widely different values for the Effective Isotropic Radiated Power (E.I.R.P). These values range from as low as -20 dBm for Body Area Networks (BAN) to as high as 30 dBm for cellular communications. This paper overviews several approaches to achieve highly efficient wireless power transmission. A Class-C amplifier operates in the 400 MHz MedRadio band and achieves measured peak output power and drain efficiency values of -4 dBm and 43%, respectively. A switched-capacitor PA achieves an average output power of 17.7 dBm, an average PAE of 27%, and an EVM of 2.6% operating with orthogonal frequency-division multiplexing (OFDM) modulation at a center frequency of 2.25 GHz.