Study of Electromagnetic Band-gap Structures－none

• Main Authors: Tsung-Han Weng, 翁崇漢
• Other Authors: Cheng-Chi Yu
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/82487321904839389854

碩士 === 逢甲大學 === 通訊工程所 === 98 === Abstract In recent years the electromagnetic band gap structure research in abundance was proposed , not only design construction and discuss the characteristic, research is of the application is a popular point, for example, in order to improve the antenna performance,increase its directivity , reduce the back radiation ,suppression the coupling effect for the electric circuit of microwave frequency band and so on…The present paper studies the electromagnetic band gap structure, can apply in the middle of the standard printing type electric circuit board easily, by way of the design and the manufacture in the standard glass fiberboard, the design of construction closure frequency band is 1.36~1.79GHz,2.36~2.52GHz 2.49~2.89GHz 2.8~3.9GHz and 5.08~6.32GHz, may apply in WiMAX ,GPS,WLAN and so on the commercial frequency band. The present paper proposed the electromagnetic band gap structure can reduce the effect of patch antenna mutually coupling, when the electromagnetic band gap structure is to agree with designing , it can the obvious suppression surface wave transmission ,in the 1.72GHz can reduces the mutual coupling 11dB in measurement. Finally , design a new type of frequency selective surface be a plate of the monopole antenna, to identify with the antenna operating frequency band to match the energy gap, The use of in the cut-off frequency of 0 ° phase of the reflection coefficient characteristics, and its bottom currents generated by the mirror (image current) and the antenna current with the phase, in order to improve the antenna performance and inhibit the substrate material surface wave generation .It can increase bandwidth and reduces the antenna size to be possible to promote 22.2%, the gain can promote 1.94dBi,reduce size 23% and increase bandwidth 520Hz. Key words: Electromagnetic band gap structure