Backscatter-Based Passive Array Transceiver Technology

With the development of communication technologies,wireless signals such as broadcast signals,television signals,and mobile phone signals are ubiquitous.The presence of these wireless signal energies at every moment in addition to meeting normal communication is actually a large part of wasted.If you can collect and use these signal energy to provide energy for communication,it will save a lot of energy.In the existing wireless transceiver systems,low noise,power amplifiers,and local oscillator generators are used,resulting in a large power consumption of the system and a relatively large volume.RFID only realizes the communication between the reader and the tag,and the communication speed between them is very low.In view of the above problems,this paper proposes a passive array transceiver technology based on ESPAR(electronicallysteerable passive array radiator).First,the passive array antenna collects energy to supply power while receiving spatial signals for re-modulation.This modulation is based on backscatter and is implemented by an analog circuit to achieve digital modulation.Compared to conventional digital modulation,its power consumption is low.This article focuses on the research of passive array transceiver based on backscatter.First of all,this paper introduces a new type of antenna ESPAR as the backscatter analog modulation antenna.Compared with other array antennas,its power consumption is very low.This is achieved by adjusting the coupling between the active and passive elements and the load between each element so as to achieve control over its directivity and increase the antenna gain.In order to increase the collection of electromagnetic energy in the system.Another study in this paper is analog modulation based on backscatter.The basic principle is to use circuit matching and reflection coefficients to achieve different digital modulations.Compared to simple RFID,its transmission rate is greater and communication can be achieved.In the era of digital communications,analog modulation and digital communication have yet to be further studied.This paper hopes to make a breakthrough in the backscatter modulation technology based on the existing research in order to bring about a modulation method while reducing the power consumption.This is also the significance and purpose of this study.The study is as follows:1)Introduce the characteristics of backscatter simulation and debugging and the development status at home and abroad.At the same time,the communication link based on backscatter modulation is analyzed.According to its characteristics,a communication system combined with ESPAR array is proposed.And proposed its communication link structure.2)Design basis for ESPAR-based backscatter analog modulation.This article introduced the technical principle of analog modulation,the design requirements and implementation methods of different modulation methods,and introduced the principle and implementation of ESPAR.And simulation and actual production test ESPAR array antenna.3)backscatter modulation transceiver system design.In this paper,four kinds of modulation methods,namely ASK,4ASK,4QAM and 16 QAM,are designed.First,for different modulation methods,first calculate and calculate different constellation points and calculate the corresponding impedance required for its corresponding analog modulation.Second,draw four kinds of analog modulation schematic diagrams and PCB design,and finally use ADS simulation software to assist welding debugging.The conditions of system ASK,4ASK and 4QAM modulation in the case of direct connection and wireless are tested,and the link of the backscatter modulation system is calculated and budgeted according to the test results.