Function-Reused Oscillator-PA for IoT Applications

To realize an energy-efficient transmitter (TX) for ultra-low-power (ULP) Internet-of-Things (IoT) applications, function-reuse oscillator–power-amplifiers (Osc-PAs) provide high efficiency and tight system integration by merging an oscillator ("Osc", either a digitally controlled, DCO, or voltage-controlled, VCO) with a power amplifier (PA) into a single block. This work presents the latest advancements in Osc-PAs for IoT applications. It covers the architectural evolution, design considerations, and limitations of Osc-PAs. Finally, the prospects of reusing and implementing TX Osc-PA to achieve RX-clock generation by leveraging mode-switching techniques in fully integrated transceivers (TRXs) will be discussed.