Co-design Of 2.4GHz Antennaand Rectifier With Highly Sensitive

Recently,Internet of things(Io T)nodes are gradually developing towards low power consumption,so that the energy harvesting circuit can replace battery to supply power for Io T nodes in its whole working life.With the advantages of wireless power supply and abundant energy sources,RF energy harvesting has great potential as an alternative to the power supply of Io T nodes.However,due to radial attenuation,the RF energy in the surrounding environment is relatively weak.As the core of RF energy harvesting circuit,the performance of antenna and rectifier directly determines the sensitivity of the system.Based on the co-design of antenna and rectifier,this thesis focuses on optimizing the sensitivity of the circuit.In this thesis,the resonance of conjugate matching between antenna and rectifier is designed to improve the voltage swing of rectifier input and the sensitivity of the system.Based on the consideration of co-design,a high-Q inductive loop antenna has been designed by modeling;An on-chip capacitor array has been designed to realize the frequency adjustability of the rectifier input impedance;Through the analysis of 1-stage rectifier,the fast optimization of the transistor size for the high-Q multi-stage rectifier has been realized.In addition,this thesis has improved the transient establishment characteristics of the rectifier based on gate dynamic bias,and optimized the power conversion efficiency of the rectifier at low input power;A low-power hysteresis voltage detection circuit has been designed to control the switch between rectifier and load path to optimize the sensitivity of the system;A charge pump circuit has been designed to boost the output of the rectifier;Finally,a voltage stabilizing circuit has been designed to keep the output voltage constant.Based on HFSS simulation,at 2.45GHz,the input impedance of the antenna is 2.33+j263Ω,the maximum gain is 1.2d Bi and the radiation efficiency is 79.4%;The overall layout of the circuit is drawn based on SMIC 180nm process,with an area of 0.277mm~2.The post simulation results show that the overall peak efficiency of the antenna rectifier co-design module is 42.95%under-22d Bm input power and300KΩload resistance;The overall static power consumption of the circuit is 23.46n W.At TT process,27℃and the input power is-36d Bm,the whole circuit can achieve 1V stable output voltage.In addition,this thesis has completed the test of rectifier chip and analyzed the error between the result of test and simulation.