Theoretical Energy-Conversion Efficiency for Energy-Harvesting Circuits Under Power-Optimized Waveform Excitation

Closed-form equations have been developed that calculate the maximum output power and energy-conversion efficiency for an energy-harvesting circuit under power-optimized waveform excitation. The theoretical model predicts how signals with high peak-to-average power ratios increase the output power available at low input powers and decrease the maximum energy-conversion efficiency at high input powers. The model shows agreement to within 0.7 dB with ideal simulated components. Additionally, the model provides a theoretical bound for a realized microwave energy-harvesting circuit prototyped at 5.8 GHz.