A Novel Design of High-Efficiency Dual-Band Inverse Doherty Rectifier for Wireless Power Transfer and Energy Harvesting

In this paper, a novel design of dual-band (DB) inverse Doherty rectifier is presented. Specifically, the proposed structure consists of two Schottky diodes, a DB quarter-wave impedance inverter (DBII) for tolerance of input power and dc load fluctuation, a DB second harmonic termination network (DBHTN) for power conversion efficiency (PCE) enhancement, and a DB impedance transformer (DBIT) for fundamental matching to the source of 50 Omega. Each sub-network is investigated in closed-form equations. For validation, a DB inverse Doherty rectifier is simulated, fabricated, and measured at two target separate frequencies of 0.915 GHz and 2.45 GHz. The experimental results show that peak PCE is achieved at 79.95 % and 77.67 % for 0.91 GHz and 2.4 GHz with 500 Omega load resistance, respectively. Moreover, the 50 % over PCE is remained within a wide dynamic range (DR) of input power, i.e., 20 dB at 0.91 GHz, and 18 dB at 2.4 GHz with 500 Omega load resistance. In addition, the 50 % over PCE within a wide DR of dc load resistance is also recorded with over 1850 Omega at 0.91 GHz, and over 1800 Omega at 2.4 GHz for 10 dBm input power. Compared to other works, the proposed DB rectifier exhibits advantages in terms of high PCE, compact size and wide DR of input power and dc load resistance.