在暗室中对窄带天线进行测量时,由于间接时域方法的测试带宽不足而无法有效地去除多径信号所产生的干扰,文中提出将现代频谱估计技术应用于此类天线的测试。以最大熵为约束条件,利用现代谱估计中的Burg算法求解接收到频域信号的AR模型参数,并对其进行频谱外推。从而在频域拓宽信号的测试带宽,在时域提高信号的分辨率,并运用间接时域测量技术精确加载时域门,达到去除多径干扰的目的。仿真和实测都验证了该方法的有效性及可靠性。

When the narrowband antenna is measured in the anechoic chamber, multipath interference can't be effectively removed by indirecttime-domain method because of insufficient bandwidth. Therefore, in this paper, the modern spectrum estimation technology is proposed and applied to the measurement of this kind of antenna. We could solve the AR model parameters of received signals in frequency-domain via Burg method, with the maximum entropy as constraint condition, and extrapolate the signal spectrum. Thus, the signal bandwidth is broaden in the frequency-domain and the resolution of the signal is also improved in time-domain, and then using indirect time-domain technology accurately to impose a time-domain gate and remove the multipath interference in anechoic chamber measurement. The results of simulation and measurement have proved the validity and reliability of this method.