Metallization Of The Inner Surface Of The Microwave Cavity Coupler By Magnetron Sputtering

With the rapid development of mobile communications, the expansion and upgrade of network and the construction of infrastructure have been the necessary requirements for the development of the domestic telecommunications industry. The indoor coverage distribution system is a huge project among them. The cavity coupler in the indoor coverage distribution system can eliminate blind spots, interference the suppression and stable signal; It occupies a very important position in the mobile communication signal distribution.In order to improve the transmission quality of signals, a layer of silver is required to cover the inside of the cavity coupler, which is called as metallization process. In china, almost all factories use the chemical plating method to metalize the inside of the cavity coupler. It can cause not only pollution but high costs, and the adhesion between the silver and the coupler is poor. These cases pose severe challenges to the metallization subject.In this paper, we introduce a novel manufacture method for the metallization of the cavity coupler combing magnetron sputtering metallization. Through modeling and simulation studies, we confirm the use of a double-layer film containing Ag and Cu, which can replace the one-layer silver film to accomplish the achievement of the microwave performance and has lower production costs. By using sputtering technique double-layer film has been successfully obtained, it has good adhesion properties and good microwave performance. It provides an environmentally friendly production method for metallization of the inner surface of the microwave cavity coupler.The main work of this paper and achievement are listed as follows:1. Modeling and simulation studies suggest that, for800M-2500MHz work band6dB microwave cavity coupler, a few microns Cu+Ag composite film system can replace tens of microns silver film for the inside metallization. It can not only improve the adhesion properties but also can save the cost of the metallization process. This provides a theoretical basis and experimental guidance for the feasibility of metallization of the inner surface of the microwave cavity coupler.2. By using sputtering technique and using double-layer film, we search on the influence of sputtering performance to the microwave performance of the coupler. We successfully achieved the metallization of the inner surface of the microwave cavity coupler by magnetron sputtering. The results show that the double-layer film at a thickness of2μm Cu/2μm Ag has high interfacial adhesion which is about4.9MPa and can obtain losses in less than1.34dB and isolation can be higher than23dB which is better than the electroplating standard. The new method of low coating costs and non-polluting can be used as an alternative method for the plating process.