报告摘要：
It is impractical to achieve a far-field and free-space environment for EMC antenna calibrations below 1 GHz due to the long wavelengths. Anechoic absorbers are also typically not large enough to achieve the requisite reflectivity performance to calibrate antennas. Standard site method (SSM) in an open area test site over a PEC ground plane is the industry standard for calibrating these low gain/low frequency antennas. Realizing most measurements are not performed in far field in this frequency range, an accurate free-space antenna factor (AF) is actually not the most accurate representation of the underlying physics. Free-space AF (or gain) is shown as a compromised average, which yields low “enough” uncertainties. However, for anechoic chamber evaluations where much lower uncertainties are desired, a more rigorous model, including near-field effects, pattern variations, and phase center movement is needed. We discuss the assumptions and limitations of the SSM and the state of the art researches on improving the accuracy for antenna calibrations for both free-space antenna factors and site validation measurements.

报告人简介：
Zhong Chen has Over 20 years of experience in antenna measurements, RF testing and EMC theory and measurements. He is Chairperson of subcommittee 1 of American National Standards Institute (ANSI) ASC C63, including responsibilities for American EMC standards for antenna calibrations (C63.5), test site validation (C63.25), and emissions and immunities measurements (C63.4). He is Chairperson of IEEE standard 1309 for calibration of electromagnetic field sensors and probes. He is Chairperson of IEEE 1128 – IEEE recommended practice for RF absorber evaluation. He is Member of United States Technical Advisory Groups (US TAG) to CISPR and IEC. He Publish more than 30 journal and conference papers on EMC measurements, antenna and field probe calibrations and applications, and other electromagnetic theory and applications. He Served as Technical committee members and chairperson for numerous conference workshops such at the IEEE EMC international symposiums, AMTA and other international conferences.
 

第251期“论坛”主请人联系方式：
孟萃 01062771962    mengcui@tsinghu.edu.cn