Research On Passive Sensing Technology Based On Backscatterin

"With the gradual maturity of wireless communication technology,the types and quantity of wireless terminal products are also increasing.As.an active device,wireless devices have great limitations in communication distance and working time due to their dependence on batteries.To solve these problems,people try to improve the energy schemes of wireless devices,such as the use of heat,light and wind energy,but these new energy sources are still seriously restricted by the use environment.In contrast,the performance of RF wireless energy transmission technology is more superior and more reliable.In addition,in order to further improve the endurance and communication distance of wireless devices,we can adopt a communication scheme with lower power consumption.Therefore,this paper aims to study the passive sensing technology based on backscatter.Using the ultra-low energy consumption characteristics of backscatter modulation technology,combined with antenna theory and the basic knowledge of RF circuit,this paper designs and implements an ultra-low power consumption passive terminal equipment with high efficiency rectification system,combined with low energy consumption reader and writer,and establishes a portable low power consumption and high reliability radar communication system.Therefore,the task of this subject is to design a common aperture broadband miniaturized dual band antenna,including a broadband cross dipole antenna responsible for obtaining RF energy and a broadband circular polarization PIFA for receiving radar signals.Then,according to the requirements of application scenarios,a high-efficiency rectifier for collecting vibration energy and RF energy,low input power and a broadband rectifier based on multistage transmission line matching network are designed.Finally,a simple and low-cost portable radar transceiver based on six port demodulation is designed and implemented,and the joint debugging between modules is finally carried out to verify the feasibility of the low-power passive sensing communication scheme.