A Compact High Efficient Voltage Doubler Constructed by Inverse Class-F Architecture for Wide Band 5G Energy Harvesting

A compact, high-efficient, inverse class-F voltage doubler (VD) is introduced for wide band 5G energy harvesting (EH) and wireless power transfer (WPT) applications. The proposed voltage doubler is suitable for the Wi-Fi (2.45 GHz band) and compatible with a band from 2.1 to 3 GHz in the fifth generation. The suggested VD is constructed by inverse class-F configuration with harmonic suppression technique. The proposed class-F ^-1 VD is built by open-circuiting the second harmonic voltage component and short-circuiting the third harmonic voltage component. The inverse class-F configuration is realized by a combination of transmission lines and discrete lumped components to compact the size. Then, the voltage and current waveforms across the diodes are reshaped to be a half-sine wave and a square wave respectively, preventing the overlap between the two waveforms and enhancing the conversion efficiency. The suggested structure gives a peak efficiency of 80.7% at 12 dBm with a frequency of 2.45 GHz. Moreover, a fractional bandwidth of 24.5% corresponding to 600 MHz of bandwidth is obtained at a conversion efficiency of 60%. While the output saturated DC voltage is 6 V with load terminal resistance equal to 2.45 kΩ. Finally, the overall dimensions of the proposed design are 12.9 × 6.4 mm ² .