Time-domain characterization for wideband antennas

对无线通信系统日益增长的需求引起了人们对合适的宽带天线的极大兴趣。为了表征这些天线，传统的测量技术已被用于频域测量，以评估一些性能，如增益，指向性和输入回波损耗。然而，增益、指向性和回波损耗是标量，它们不能反映远场的相位变化，这对宽带天线的性能有很大的影响。因此，为了检测宽带天线的性能，不仅需要进行频域测量，还需要进行时域表征。针对这一问题，本文提出了一种用于宽带天线的射频测量时域表征装置。该系统主要由两个重要的仪器组成：一个脉冲射频发生器和一个高分辨率数字存储示波器，具有非常低的上升时间（60 ps）。为了避免这些测量过程中的干扰和多径现象，建议的装置将安装在我们已经在INRS-EMT建造的消声室内。本实验装置的主要目的是利用短脉冲脉冲发生器和高分辨率数字存储示波器测量被测天线的最小脉冲畸变。所要求的仪器将补充我们在INRS-EMT射频实验室已有的设备。目前申请的目标是：(i)为未来的无线通信系统开发和测试新的高效宽带天线，符合加拿大高科技工业的具体需求，以及（ii）培训高素质人员，以应对我们社会的科学和技术挑战。

The increasing demand for wireless communication systems has attracted significant interest in suitable wideband antennas. To characterize these antennas, conventional measurement techniques have been used for  frequency domain measurements in order to evaluate some performance such as the gain,  directivity and input return loss. However, the gain, directivity and return loss are scalar quantities and they do not indicate the phase variation of the far-field, which has a significant impact on the performance of wideband antennas.  Therefore, to examine the performance of the wideband antennas, not only frequency domain measurements are required, but also time-domain characterization is necessary. For this issue,  an RF measurement time-domain characterization setup for wideband antennas is proposed in this application. This system is mainly composed of two important instruments not available in our laboratory at INRS-EMT: a pulse RF generator and a high resolution digital-storage oscilloscope with very low rise time (60 ps). In order to avoid interference and multipath phenomena during these measurements, the proposed setup will be installed inside our anechoic chamber, which has already been built at INRS-EMT.  The main objective of  this experimental setup is measuring the minimal pulse distortion of the antenna under test by using a pulse generator with a short pulse and a digital-storage oscilloscope with high resolution. The requested instruments will complement pieces of the  equipment already available in our RF laboratory at INRS-EMT. The objectives of the present application are, (i) developing and testing new efficient  wideband antennas for future wireless communication systems, consistently with the specific needs of the high-technology Canadian industry, and (ii) train highly qualified personnel to respond to the scientific and technological challenges of our society.