Transmitters for body sensor networks: A comparative study

Transmitters for ultra-low-power sensor networks are continuously evolving to transmit low output power in a highly efficient manner. To this end, various architectures have been introduced that trade off distinct advantages and disadvantages. A comparison of several recent transmitter architectures is presented in terms of power efficiency and it is shown using theoretical calculations that certain architectures are better suited to efficient ultra-low-power transmission. Finally, as a proof of concept, a highly efficient power amplifier (PA) with a maximum output power of -4 dBm is demonstrated in 0.13 μm CMOS. It achieves a maximum drain efficiency of 43%.