Design And Implementation Of Self-powered Wireless Signal Transmitter

The development of the Internet of Things(Io T)is driving the widespread adoption of communication between large-scale sensors,embedding network connections into the vast number of small computing and storage devices(associated with people,vehicles,homes,cities,environments and other factors)to make "communication" between everything a reality.Radio Frequency Identification(RFID)tags,a key application of the Io T,potentially connect hundreds of millions of devices to the Io T.However,large-scale deployment of such devices brings high costs,high energy consumption,maintenance overhead for replacing depleted batteries,and inconvenience of deployment due to the size of the devices.And trapped by the limitation of RFID tag communication distance,the current passive RFID system becomes the biggest challenge for Io T.As a result,there is a growing interest in battery-free,low-power sensor tags(Tags).The dependence of tags on batteries is eliminated by using energy harvest from the surrounding environment(e.g.,light,thermoelectric,or wireless signals).However,it's kind of difficult to transmit using conventional wireless transmission mechanisms with tiny intermittent energy.Backscatter communication overcomes this limitation by consuming power at the microwatt level.However,due to the path loss and power limitation problems,existing backscattering techniques can only achieve short-range,low-rate communication,which is still having lacking compared to mature wireless communication technologies.In this paper,we focus on a new low-power backscattering communication technique.Based on previous research,we propose a novel tunnel diode-based low-power backscatter signal transmitter.The signal transmitter has the characteristics of low power consumption and high reflected power.Supplemented with the support of energy harvesting technology,it provides a solution for battery-free,long-distance wireless communication.The main work of this paper is as follows:1.A new type of low-power backscatter signal amplifier based on tunnel diode is designed and implemented.With the tunnel diode GI307 A as the core,the design and realization of the circuit are completed by using its negative impedance characteristic.Through the system test in the UHF frequency band,the amplifier can achieve a reflection gain of up to 50 d B under an incident signal as low as-50 d Bm,and its bias power is as low as 100?W,with better performance than the results of similar studies.2.Based on the analysis of the theory and performance of the tunnel diode,as well as the research on the modulation method of backscatter communication,we designed the signal modulation module directly on the basis of the backscatter amplifier.The dual functions of signal amplification and phase modulation(BPSK)have been successfully implemented on the backscatter amplifier circuit.Which has obvious advantages over conventional binary amplitude keying modulation(OOK)modulation,the modulation and amplification discrete circuit,it has advantages obvious.3.An energy harvesting system to power a wireless signal transmitter is discussed,and an energy harvesting circuit based on weak light illumination is designed for meeting the basic power consumption requirements of our designed wireless signal transmitter.