Research On Wideband Pattern Reconfigurable Built-in Antenna For Mobile Phone

With the rapid development of the communication technology, the mobile phone is adevice of the communication terminal, it’s experiencing from the3rd-generation (3G) to theLong Term Evolution (LTE). In order to be compatibility （with2G/3G systems）in2G and3G system, future4G-LTE system (covering) will cover at least eight bands. The ordinaryantenna is difficult to meet the requirements, consequently the Ultra-Wideband (UWB)antenna begin to research and application. At present, The realization technology of the UWBantenna is includes two points: Multiple-Input Multiple-Output (MIMO) technology andreconfigurable technology.In order to achieve the multi-functional, high-rate and large-capacity communicationsystem, the MIMO technology has become one of the core technologies of the LTE system.But MIMO system is requires multiple antennas, not only it will increase the structuraldimensions of the device, but also it will increase the Electromagnetic Compatibility (EMC)problem of the system. The reconfigurable antenna structure has the advantages of small size,light weight, good electrical properties, wide operating band and electromagnetic radiationlow et al, and then, the reconfigurable antenna attracted the attention of the mobile industryThis paper studies pattern reconfigurable antenna, The main study work and innovations canbe summarized as follows:1. Currently, the vast majority atennas of mobile phone on the market are internalmonopole antenna or external antenna. In order to reduce radiation of the antennas on thehuman body, this paper presents a quad-band stacked radiation pattern reconfigurable antennafor the mobile phone integrated with MEMS switches. The numerical results show that thereconfigurable antenna with omni-directional and dual-directional radiation characteristics,operating band coverage the DCS, PCS, UMTS and ISM band. Due to the gain of the afterflap of the antenna pattern is low, therefore, the pattern of the reconfigurable antenna formobile phone can effectively reduce the electromagnetic radiation on the human body, toachieve “green communication”.2. In order to meet the needs of mobile phone multi-functional and broadband, the paperdesigned a broadband stacked radiation pattern reconfigurable antenna for the mobile phonebased on the load switch technology. The reconfigurable antenna for the mobile phone has two directional patterns working in the frequency band from1.57GHz to2.5GHz (VSWR≤2),operating band coverage the DCS, PCS, UMTS and ISM band. and the omni-directionalpattern works in the frequency band from1.5GHz to2.5GHz(VSWR≤2), to achieve broadbandcommunication.3. Currently, no coverage about the wideband radiation pattern reconfigurable antennafor the mobile phone At home and abroad. combining a large number of experimentalsimulation data, analyze and summarize the variation of the pattern reconfigurable antennaelectrical parameters under the conditions of the different factors. The results of optimizationformula are better compared to the results of the traditional formula.4. This paper presents a novel radiation pattern reconfigurable antenna based on themicrostrip patch Yagi-Uda antenna in the X-band, the physical size of the antenna is lesscompared to the traditional Yagi-Uda antenna, and having omni-directional and directionalradiation characteristic, and provide a reference for design of the wideband direction patternreconfigurable antenna.