Wi-Fi backscatter communication has lower power consumption and lower cost than active Wi-Fi. However

most of the current researches have the problems of large power consumption of field programmable gate array (FPGA) and high manufacturing cost of application specific integrated circuit (IC). Therefore

a passive Wi-Fi backscatter communication method based on microcontroller (MCU) is proposed. The low-frequency MCU is used to generate the Wi-Fi backscatter modulation waveform with nanosecond timing accuracy. After the low power design and optimization

the MCU power management based on energy harvesting and passive system design are carried out. And the passive Wi-Fi prototype is demonstrated for the first time. Tests show that the instantaneous power consumption of communication is 1.8mW

which is 2~3 orders of magnitude lower than that of active Wi-Fi. The system has a standby power consumption of 2.5μW and an effective communication distance of 15 meters. It is compatible with existing commercial Wi-Fi devices and has low cost and no battery.