|时间: 2009-01-06||发件人: admin||消息来源: nano@seu|
题 目：Could the antenna gain pattern be expressed in energy in stead of power?
报告人：Prof. Dau-Chyrh Chang (张道治 教授) ----- IEEE Fellow
时 间：2009年元月12日（一） 下午 15:30~17:30
地 点：东南大学 （四牌楼校区）李文正楼 六楼 612会议室
主 办：IEEE AP-MTT-EMC Joint Nanjing Chapter
In general, the limited antenna power patterns in frequency domain are used to describe the antenna performance. It is enough to describe the antenna performance in narrow band communication systems. However, the limited antenna power patterns in frequency domain are not enough for ultra wideband (UWB) antennas or arrays in communication systems. The energy pattern of antenna is the total response of power patterns in frequency domain. It will be easier to describe the energy pattern instead of power pattern for UWB antennas.
In this keynote speech, including electromagnetic energy, electromagnetic power, Fourier transform between pulse width in time domain and frequency spectrum, theoretical analysis of energy pattern, energy gain, energy directivity and energy efficiency will be defined.
In order to verify above theory, Yagi-Uda antenna, multi-beam smart antenna, UWB bow-tie slot antenna, UWB comb taper slot antenna, and UWB array at different spacing are studied and measured by the impulse time domain radar system.
In the antenna array system, the grating lobe will appear in the power pattern when antenna spacing is larger than one wavelength, but the energy pattern does not generate any grating lobes or any other sidelobes. The detail contents are illustration in the speech.