Design And Implementation Of A Sensor System Based On Stimulataneous Wireless Information And Power Transfer

Wireless sensor is widely used in military,national defense,environmental science,health care,disaster relief and in other fields it also has a wide range of applications.Besides, it has been extended to the field of space exploration,where it is used to detect and recognize space target, test space environment, etc.The wireless technology that the wireless sensor used currently can only transmit information,and cannot carry electricity power.This technology can not achieve parallel transmission of information and energy.The power is generally supplied by battery power or power cord,both of which severely limit the application of the sensor in many occasions.For example in the sensor applications of underground buried,dangerous environment,space vehicle,the price of replacing the battery or the laying of cables is great,and there are possibility that cables moving or winding can bring risk.To solve this problem,this paper designed a system of Stimulataneous Wireless Information and Power Transfer by referencing frequency division multiplexing in communication technology.This system can realize the power supply of sensor system and data transmission simultaneously under the same antenna.This article designs a SWIPT system that includes a microwave energy transmission subsystem and a communication subsystem.This two subsystems through their frequency selective network to isolate microwave energy information and data information from mixed data/energy signal.In this paper,a high-gain amplifier,a high input and high-efficiency microwave rectifier circuit,a low reflection antenna are designed in the microwave energy transmission subsystem.It could maximize the DC power in the sensor nodes.A low insertion loss frequency selective network and a antenna impedance matching at the frequency of communication are designed in the communication subsystem.It can reduced the power consumption of communication information loss greatly.The method of low-power consumption is used to reduce energy consumption.According to the above methods,this paper designed the system of Stimulataneous Wireless Information and Power Transfer and tested the microwave energy transmission subsystem, communication subsystem and the whole communication system.The test results show that two subsystems can achieve parallel transmission of information and energy when they share a pair of antenna.It confirms the correctness of the designed system in this paper.In the microwave energy transmission subsystem,the The maximum output power of microwave energy is 36.8dBm,and the rectifier efficiency of microwave rectification unit can reach 50% when the input is 25dBm.The power can be tansferred as far as 1.6m. After calculation, this article verifies the DC power that the sensor node received is enough to work.It also can show that the communications unit can complate collecting,transmitting and showing the temperature of the nodes at 2400bps.