The Basic Research Of RFID Tag Antenna Using Jet Printing

RFID?radio frequency identification?technology is a technology which can use radio waves to achieve data.It has been integrated into the manufacturing,food testing,book management,and other fields because it has some advantages such as non-contact,penetrability and barrier-free reading.The tag antenna as an important part for RFID systems,it?s preparation methods is more and more people's attention.The preparation methods of the tag antenna are:coil winding method,electroplating method,etching method,screen printing,inkjet printing,etc,but the tag antenna prepared by these methods exists some deficiencies in different degrees such as:high cost,complicated process,pollution environment and so on.Based on these analysis,a new method was proposed to prepare RFID tag antennas by combining micro-droplet jet printing with chemical deposition in this paper.In order to use this method to prepare RFID tag antenna,a pneumatic double nozzle droplet inject system was developed.In this paper,Wire forming experiments were carried out on the coated paper substrate including lattice deposition tests,silver nitrate into line tests at the different speed,the wire of different width forming tests and wire forming experiments were sudied at different speed on the cotton fabric.The present work laid the foundation for the prepartation of RFID tag antenna.The pneumatic double nozzle droplet inkjet system was composed of droplet generation module,jet control module,graphics acquisition module,motion control module.The STM32 micro control system was mainly to implement coordinated actions of the droplet generation,mobile platform movement,coordinated actions etc.Wire forming experiments were carried out on different substrate.Wire forming experiments were carried out on the coated paper substrate including silver nitrate and ascorbic acid lattice deposition tests,silver nitrate into line tests at the different speed,the wire of different width forming tests and the resistivity test of the wire.The result based on size measurement and calculation on the lattice deposition tests indicated that the uniformity of the droplets was good.The edge smoothness was associated with the movement speed of substrate on silver nitrate into line tests at the different speed.The method of multiple columns overlap was adopted in order to print out a wide wire.The resistivity of the wire on the coated paper substrate was1.57×10^-5?.m by testing and calculating.Wire forming experiments were carried out on the cotton fabric.Due to the spread phenomenon on cotton fabric,the surface of the cotton fabric was pretreated using TF449A.Wire forming experiments were sudied at different speed on the cotton fabric.The breakpoints situation would get some improvement but conductivity was bad when the speed of the substrate was small;The breakpoints situation would occur when the speed of the substrate was large,the conductivity of the wire can be increased by multilayer printing.Half wave dipole antenna simulation and experimental research were carried out.The size and shape of the half-wave dipole antenna were designed.The Ansoft HFSS software platform was used to simulate the half-wave dipole antenna on coated paper and cotton fabric substrate.The resonant frequency,the resonance point return loss S₁₁ parameters of the half wave antenna were got.Finally,under the better experimental conditions,the antennas were printed on the two substrates.Parameters of half-wave dipole antenna were tested.The half-wave dipole antennas prepared on two substrates were monitored by a vector network analyzer Agilent E5071B.On the coated paper substrate,the resonant frequency of the antenna was 2.07 GHZ,the antenna parameter S₁₁ was-26.91 dB,and the antenna bandwidth was 1.63².60 GHZ.On the cotton fabric substrate,the resonant frequency of the antenna was 2.12 GHZ,the antenna parameter S₁₁ was-14.66 d B,and the antenna bandwidth was 1.84².70 GHZ.The test results were in good agreement with the simulation results,showing the feasibility of using micro-droplet jet printing and chemical deposition for preparation RFID tag antenna.