The Research On Electromagnetic Compatibility Technique In Broadband Wireless Access Base Station

Broadband wireless access technology is one of the main developmentes for broadband communication in 21 century. It is the pivotal technology to solve the problem of"Last one kilometer"access and"Bandwidth bottleneck"for 3G mobile users. At the same time, broadband wireless access technology is the optimal scheme that it fleetly solves problems of integrated collocation line for the ancient city zone and informatization of outlying country.With wide application of broadband wireless access technology, the EMI phenomenon is more and more serious among communication systems and inner communication base station. The EMC problem of broadband wireless access base station and intersystem frequency interference of 3G communication systems are very important. For these problems, the researches are as follows:Firstly, the EMC problem of broadband wireless access system was discussed, and the structure and consisting characteristic for different broadband wireless access systems were analyzed. Three EMC characteristics are summarized as follows:1. The interference of LEMP on base station;2. The interference of wide frequency Radiate on information equipment;3. The intersystem Frequency interference among 3G communication systemsSecondly, LEMP was researched. Mechanism and Spectral characteristic of LEMP were analyzed in detail. The attacking form of LEMP to base station was discussed. The protective area of lightning rod was analyzed and simulated with computer. A standpoint using"global five lightning rod"to increase base station capacity of resisting flank attack lightning is proposed..According to principle of Faraday Screen Cage, a standpoint using"accessorial earth net by mixed grounding"to increase base station capacity for discharging quickly as lightning rod lead lightning is presented.Thirdly, a mathematic model for calculating ground electric field was established, and the change of ground electric field during thunder activity was analyzed. According to reference, the concept for critical of ground electric field was brought by analyzing ground electric field and atmosphere electric field.According the concept for critical of ground electric field, a mass of experimental data had been obtained by surveying the changing curves of ground electric field during thunderstorm on the spot. The threshold of ground electric field that triggers the first lightning strike was brought, and"smart base station power supply against LEMP"was developed. The"power supply"was practicality tested in QingXin public information wireless network, and the test had gained success. The"power supply"had acheived patent.(Patent No. ZL 03 2 26526.3,...