Analysis and Measurement of EMI/EMC in a WLAN Communication Unit

• Main Authors: Chuan-Chou Chiang, 江權洲
• Other Authors: Hsing-Yi Chen
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/15023631305810904647

碩士 === 元智大學 === 通訊工程學系 === 93 === The finite-difference time-domain (FDTD) method is used to study electric fields distributions on the printed circuit board (PCB) built in a wireless local area network (WLAN) communication unit. In the simulation of the PCB and WLAN communication unit, an equivalent material obtained by the effective material property technique is considered to model the metallic material, epoxy resin substrates of PCBs, cable and air. Simulation results of electric field distributions on the PCB are presented and compared with those obtained from measurement data for an opened metallic case of the WLAN communication unit. From simulation results, it is found that maximum electric fields on a test plane over the PCB with a height of 1 and 2 cm are obtained to be 0.25~0.32 and 0.15~0.25 V/m for the RF power of 17.2 dBm at 2.4 GHz under the condition of an opened WLAN communication unit, respectively. Comparing measurement data of electric field distributions on test planes with a height of 1 and 2 cm over the PCB, with those obtained by FDTD simulations, it is found that simulation results make a good agreement with measurement data for an opened WLAN communication unit. From simulation results, it is also found that a resonant effect with a factor of 2 in the magnitude of electric fields on a test plane with a height of 1 cm over the PCB occurs for a closed WLAN communication unit.