| With the mobile communication technology mushrooming, mobile terminals, especially mobile phone, have become an essential communication tool in people’s daily life. As a pre-version of4G terminal, LTE mobile terminals subject to more and more attention because they adopt MIMO technology that can greatly increase channel capacity under the condition of no increase of spectrum resources and antenna transmit power. At the same time, today’s mobile communication terminal is no longer limited to single antenna terminal and there appeared multi-antenna terminals including multi-mode terminals and multi-standard terminals. In order to ensure the quality of telecommunication, it is necessary to make accurate assessment of radiation properties of these terminals. The assessment methods are active testing method and passive testing method. Active test focuses on characteristics of the cell phone’s radiation from the total transmit power and receive sensitivity. Passive test focuses on radiation performance of mobile phone’s antenna parameters. Based on these two evaluation method, the paper carried out the radiation property study for LTE terminals, LTE multi-mode terminal and LTE multi-standard terminal. The main contents are as following:First, the paper introduces research background of radiation performance of LTE terminal, and also investigates its research status at home and abroad. Second, the article describes the LTE terminal’s accurate modeling and some indicators of characteristics during simulation process. Third, the paper completes a MIMO antenna design for LTE terminal which covers2570-2620MHz frequency band, and also studies the influnce of ground structure and medium plate lenghth on antenna’s isolation and radiation performance. It turns out that the modified MIMO antenna system has a good performance. In addition, LTE terminal model is constructed based on the designed MIMO antenna unit. The radiation performance of the LTE terminal is also analyzed. Fourth, the paper studies radiation performance of LTE multi-mode terminal. In this part, the article uses the common WLAN and Bluetooth application unit as an example for analysis, and also analyzes impact of the application modules on MIMO antenna by comparing with the LTE terminal. Finally, the article describes LTE multi-standard terminals and takes LTE/GSM terminal as an example to study radiation performance of LTE multi-standard terminal. Both LTE/GSM terminal’s single and dual standby modal are analyzed. The impact of the multi-standard on MIMO antenna is also investigated. |
