| With the continuous development of science and textile technology, textile breakthroughs are moving away from the original scope of hot insulation and beautification,towards functionality and intelligence. As an important member of the antenna family,microstrip antennas not only have a good antenna performance, but also have manyother advantages such as manufacturing, packaging, thin profile and lightweight etc..Textile-based, wearable, flexible microstrip antennas incorporated using directprinting techniques, combine microstrip antennas with flexible textiles. The resultanttextile materials not only have good wearability-softness, moisture absorption andbreathability, but also microstrip antennas. Therefore, they have broad prospects andpositive significance.This research is based on the effect of dispersing. Firstly, to find out suitablewettability of fabric, the fabric wettability is evaluated according to the measurementsof wicking height and wetting time. The liquid dynamic diffusion is investigated interms of the measurements of diffusion area and regional coating effect. On the basisof the above research, the manufacture of copper layers is studied under the differentconditions, including with or without complexing agent, dispensing velocity, pressureand cycle-index. Finally, the antenna performance is characterized by the return loss.The specific research contents are as follows:The evaluation of fabric wettability. In order to find out the optimal wettingrange that is suitable for the requirements of dispensing, samples with varyingwettability are prepared. The wicking height and wetting time of samples made fromdifferent types of fiber and structures, and treated with different finishing agents istested. A study of liquid dynamic wetting is carried out making use of the dynamicparameters, dynamic contact angle and moisture absorption curve. The results showthat, the looser the fabric structure, the more the existing hydrophilic groups, andhigher surface energy can improve the wetting capacity of the fabric. Cotton A, Cotton B, PET A and PET B have average advancing contact angles ofrespectively70.32°,59.90°,94.13°and97.53°. Different finishing agents havevarying effects on the fabric surface. Polyether modified silicone TF405and modified2D resin TF655have a certain improving effect on fabric surface energy followed bythe cationic fat amide TF449and natural wax emulsion TF811. and Amino siliconeTF437and three proofing finishing agent TG410HN are characterized by strongrepellent properties, thus a poor effect on fabric surface energy. The total range oftheir average advancing contact angles is from67.95°to115.36°.The determination of the suitable wettability of fabrics. In order to meet thedispensing means of manufacting copper layer, dispersing test is carried out foraforementioned fabrics. The results show that, with the increasing of average contactangle, the diffusion area of droplet decreases from0.89cm2to0.03cm2under thecondition of regional coating. If the average advancing contact angle is below82.33°,solution can easily penetrate the fabric, while if it is greater than90°，the solution cannot penetrate. When the dynamic contact angle is in the range of82.33°~90°and thewetting time is about6s, and the requirements of wettability to manufacture clearerconductive copper layers can be met.The process optimization for the manufacture of copper layers. In order to gethomogeneous and dense copper layers with a good electrical conductivity thepreparation of copper plate under the different conditions has been studied, with orwithout complexing agents, dispensing velocity, pressure and cycle-index. The resultsshow that complexing agents improve the fastness of the layers, because of thehydrogen evolution phenomenon which is caused by redox reaction. The lowersolution concentration, the higher dispensing velocity and cycle-index have been usedto reduce the number of the pores on the surface of copper plating, and to meet therequirements of electrical conductivity and the fastness of the copper layers.The assembling of microstrip antenna. The radiation, substrate and internal planelayers can be glued by3M glue spray along thetransmission line feed. What requiresspecial attention is the homogeneousness and uniformity of gluing. One can use thestandard SMA splice to connect these three parts, there after fasten by electric soldering iron, and save for testing.The test of microscrip antenna’s return loss. The working frequency of microstripantenna can be up to2.45GHz, while its radiation ability remains lower than themicrostrip antenna with a copper foil radiation layer. The change of dielectric layerthickness has little effect on the return loss. |
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