High-Efficiency 5.8-GHz Rectification Enabled by Doping-Optimized Quasi-Vertical GaN SBDs

In this paper, the design and implementation of a high-efficiency, wide-dynamic-range 5.8 GHz rectifier is presented, enabled by doping-optimized quasi-vertical gallium nitride (GaN) Schottky barrier diodes (SBDs). To address the critical trade-off between forward conduction and reverse blocking characteristics at C-band frequencies, GaN SBDs with varying drift layer doping concentrations are fabricated and analyzed. Nonlinear loss modeling and simulations reveal that the device with a drift layer concentration of 2×1017 cm-3 yields the optimal performance. A doping-optimized quasi-vertical GaN SBD is fabricated, exhibiting excellent characteristics with a low turn-on voltage of 0.30 V, a breakdown voltage of 30 V, and a high cutoff frequency of 142 GHz. Leveraging the GaN SBD, a 5.8 GHz rectifier is designed with a peak efficiency of 70.8% at 15 dBm, and a wide power dynamic range of 19 dB (6-25 dBm), validating the proposed optimization strategy for C-band wireless power transfer.