Research And Design Of Rectifier Antenna In RF Energy Harvesting System

With the research of wireless communication,internet of things and semiconductor integration,low-power,miniaturized wireless sensing devices have been developed and applied.RF energy collection provides new ideas for the energy supply of wireless sensor equipment and solves the problem of power supply in wireless sensor networks.The most critical part of the RF energy collection system is the rectifier antenna.It is mainly composed of the receiving antenna and the rectifier circuit.Its main function is to convert the low input RF power in the environment into usable DC power.Its overall performance directly determines the overall system performance.Energy harvesting efficiency.This article mainly conducts in-depth research on the RF energy receiving antenna and rectifier circuit,and completes the design of the rectifier antenna.(1)A single-layer single-feed dual-frequency circularly polarized antenna with a cross-patch is designed.The dual-frequency patch antenna provides a new method for designing other multi-frequency circularly polarized antennas.A horizontal stub is introduced at the upper end of the long arm of the cross patch,and an acute angle is extended from both ends of the short arm to achieve dual-frequency circular polarization at low frequency(1.64GHz)and high frequency(3.45GHz),respectively.The antenna size designed in this paper is 53 60mm2,which can be applied in the WIMAX frequency band.The experimental results show that the impedance bandwidth of the antenna is 250MHz(1.55-1.8GHz)and 1440MHz(2.2-3.64GHz),and the 3dB axial ratio bandwidth in these two frequency bands is 250MHz(1.52-1.78GHz),respectively.And 520MHz(3.08-3.6GHz).Antenna collection efficiency reaches 70%.The antenna was printed and tested,and the measurement results were basically consistent with the simulation results.(2)Two single-frequency rectification circuits are designed.The circuit structure adopts a double-voltage rectification structure.The components adopt a rectifier diode model HSMS-286C,a load of 1000Q and a capacitance of 100pF.The single-frequency rectifier circuit with a center frequency of 1.64GHz is matched with a T-shaped structure.When the frequency is 1.64GHz and the input power is 12.5dBm,the rectification efficiency is 65%.The single-frequency rectifier circuit with a center frequency of 3.45GHz has a T-shaped matching network.When the frequency is 3.45GHz and the input power is 13.9dBm,the rectification efficiency is 62%.A dual-frequency rectifier circuit with a frequency of 1.64GHz and 3.45GHz is designed.The circuit structure adopts the Greinacher bridge type full-wave rectification structure.The components adopt a rectifier diode of type HSMS-286C,a load of 1000? and a capacitance of 100pF.The matching network of the two branches uses a T-shaped structure.When the frequency is 1.64GHz and the input power is 15.1 dBm,the rectification efficiency is 60.5%;when the frequency is 3.45GHz and the input power is 15.1 dBm,the rectification efficiency is 64.9%.(3)Combine the receiving antenna with the rectifier circuit to complete the design of the rectifier antenna and perform physical tests.When the frequency is 1.64GHz and the input power is 15.1dBm,the rectification efficiency is 60.5%;when the frequency is 3.45GHz and the input power is 15.1 dBm,The rectification efficiency is 64.9%.