电磁波激励下天线的响应特性分析  

Analysis of response of antennas to electromagnetic waves excitation

作　　者：赵振江[1] 杜正伟[1] 龚克[1] 

机构地区：[1]清华大学微波与数字通信技术国家重点实验室,北京100084

出　　处：《电波科学学报》2005年第4期418-423,共6页Chinese Journal of Radio Science

基　　金：国家高科技发展计划资助项目

摘　　要：应用互易定理推导出了电磁波激励下天线的耦合长度和耦合面积的表达式,这两个物理量可以表征天线的响应特性。针对对称振子天线,在不同来波照射方向和端接不同带宽的接收机这两种情况下,计算获得了耦合长度和耦合面积。计算结果表明,工作频率为2GHz的对称振子天线的耦合长度随着接收机带宽的变化在频率f=2+4n(GHz)(n=0,1,2...)或f=4n(GHz)(n=1,2...)附近出现谐振峰;而耦合面积随来波入射角度的增大而增大,随接收机带宽的减小而减小。Expressions of the coupling length and the coupling area of an antenna to electromagnetic waves excitation are deduced with the reciprocity theorem. These two variables can be used to describe the response of antennas. As an example, a centre-fed dipole is analyzed using the obtained expressions. The coupling length and the coupling area of a centre-fed dipole are obtained and analyzed under the conditions that it is illuminated by waves with different arrival angle and connected to a receiver with different operating bandwidth. The results show that, for the dipole operating at 2GHz, the coupling length has a set of resonance points at the frequency f=2＋4n （GHz） （n=0,1,2...） or f=4n （GHz） （n=1,2...） responding to the various bandwidth of a receiver; the coupling area increases with the increasing of the arrival angle of a wave and decreases with the decreasing of the bandwidth of a receiver.

关 键 词：互易定理 耦合长度 耦合面积 对称振子天线 

分 类 号：TN82[电子电信—信息与通信工程] TN97