建立微波标准场的高性能天线的研制

Development of high performance antennas for establishing microwave standard fields

建立微波功率密度标准是解决微波场强的量值溯源和计量问题的关键，而建立精确的宽频带、宽量程微波功率密度标准装置离不开产生微波标准场的高性能微波天线.通过理论计算和仿真分析研制了频率覆盖1～18 GHz的5付角锥形喇叭天线，用以建立量程为10mW/cm^2的宽频带微波功率密度标准装置.采用三天线法对实际制作完成后的天线的增益和驻波比进行了测量.结果表明，所研制的天线的性能完全符合性能设计要求.此外，还研究分析了由天线在微波功率密度标准发生装置中所引入的不确定度，给出了其对微波功率密度标准发生装置的总不确定度的贡献.结果表明所研制的天线完全符合宽频带、宽量程和高精度的微波功率密度发生装置的要求.

Establishing the microwave power density standard is very important to solve the problem of affiliation and metrology for microwave field strength. While establish the precise, wide frequency band and wide measurement range power density standard generation equipment, qualified antennas must be used to transmit the standard microwave field. In this paper, five horn antennas are developed through theoretical analysis and numerical modeling, whose frequency range is from 1GHz to 18GHz, to setup the microwave power density standard generation equipment with the maximum power density value of 10mW/cm^2. After the antennas are made, the gains and the voltage standing-wave radios （VSWR） of them are measured by three-antenna method. The measurement results show that the performances of the antennas are very satisfied. Finally, the uncertainty induced by these transmitting antennas during the generation of the microwave power density standard is studied. It is concluded that the developed antennas are satisfy completely the wide band, wide measurement range and high accuracy requirements of the microwave power density standard generation equipment.