Design of high-frequency Ga2O3 Schottky barrier diodes for microwave wireless power transmission

Ga2O3 Schottky barrier diodes (SBDs) are expected to be applied to rectenna circuits used for microwave wireless power transmission due to its superior physical properties. We first designed high-frequency Ga2O3 SBD structures to maximize a cutoff frequency using a device simulator. Then, the simulated device characteristics obtained for the optimized Ga2O3 SBDs were transferred to a circuit simulator to calculate a power conversion efficiency (eta) of a rectenna circuit operating at 24 GHz. In the case of the SBDs having an n+-Ga2O3 access layer with an extremely large electron density of 4 x 1020 cm-3, the maximum eta was estimated to be as high as about 80% irrespective of the anode area. These results suggest that Ga2O3 SBDs have high potential for rectenna circuit applications, especially for frequencies above 10 GHz.