Research On Power And Data Integrated Wireless Sensor Based On RF Energy Harvest

Wireless sensors are being more commonly employed as Internet of Things（IOT）technology advances.The application environment becomes more flexible since wireless sensors deliver data wirelessly.However,there are still certain issues with wireless sensors’ power supply mode.The downside of wired power supply is that it has a high construction burden and is difficult to transform.It’s time to replace the battery power supply.The battery must be replaced in the battery power supply mode.It is simple to create corrosion and damage to the sensor if it is not replaced in a timely manner.Harvesting RF energy to power wireless sensors is a new power supply mode that not only solves the problems caused by the old wireless sensor power supply mode,but also maintains the benefits of wireless sensors while making their use more comfortable.This thesis investigates RF power collection technology,designs a wireless sensor with a power supply and data integrated on the basis of RF energy harvesting technology,employs RF energy harvesting technology to realize long-distance wireless power supply to the wireless sensor,and wirelessly transmits the data collected by the wireless sensor.To begin,this thesis investigates the propagation law of an RF electromagnetic wave signal in space,as well as the principle of a power receiving circuit that converts an RF signal to a DC electrical signal.An impedance matching circuit and a voltage doubling rectifier circuit are included in the RF energy harvesting circuit.The antenna impedance and the voltage doubling rectifier circuit are impedance matched by the impedance matching circuit,and the voltage doubling rectifier circuit converts the RF signal to DC signal.The RF energy harvesting circuit is designed in this thesis,and the circuit’s performance is proven by simulated experiments.A voltage doubling rectifier circuit with resonant network is designed based on the design of a voltage doubling rectifier circuit,which increases the output of the voltage doubling rectifier by nearly 2.5 times.This thesis develops a power boost management circuit that can achieve maximum power point tracking and low-voltage boost in order to effectively improve the output voltage of an RF energy harvesting circuit.For wireless sensing,the enhanced power output is stored in a super capacitor.Secondly,because RF energy harvesting technology provides limited energy,this thesis examined the energy consumption of various sections of wireless sensor devices and finalized the low-power scheme design.Selecting a low-power microprocessor,programming the microprocessor software to achieve energy consumption scheduling management control,constructing a sensor acquisition system with a low-power temperature and humidity sensor to collect environmental data,and using a low-power Bluetooth module to achieve wireless sensor data transmission.Finally,this thesis accomplished the design of RF energy harvesting circuits,power boost management circuits,and wireless sensor circuits,as well as the physical testing and integrated experimental testing of each circuit.When the RF wave power intensity is more than-10 d Bm within two meters of the transmitting source,the testing findings demonstrate that the RF energy harvesting circuit has a voltage output of more than 710 m V.The boost management circuit can boost input voltages above 0.1V,and the boost output can meet wireless sensor working voltage requirements.The super capacitor stores the boost management circuit’s output.When both ends of the super capacitor reach 4.3 volts,the stored electric energy is sufficient to power the wireless sensor and enable data collecting and transmission.To summarize,by harvesting RF energy,the power supply and data integrated wireless sensor based on RF energy harvesting technology can meet the needs of data gathering and wireless data transfer.