942 MHz High Efficiency Rectifying Circuit at -20 dBm Input Power

A rectifying circuit is designed and optimized for operation in the GSM 942 band with low power input (-20 dBm). The circuit consists of rectifying diode, matching network and harmonic rejection filter. According to the simulation results at -20 dBm power input, the conversion efficiency is 31.2% and the output voltage is 0.12 V at 5 kΩ load. In order to provide enough power for a power management integrated circuit (PMIC), a structure of 4 rectifying circuits in parallel is designed and optimized in Advanced Design System. The final electromagnetic simulation results show that the conversion efficiency is 47.8% and the output voltage is 0.31 V at 5 kΩ load with -20 dBm power input. The design of rectifying circuit is quite easy and practical which can be used in wireless energy harvesting.