Tapered Balun of a UWB UHF coupler for GIS PD detection

GIS PD 검출용 UWB UHF 커플러의 테이퍼형 발룬

The UWB UHF coupler for GIS PD detection needs a balun (balance to unbalance transformer) to show its inherent UWB characteristics. In order to reduce the size of the balun and to make it practical in the conventional GIS, a novel tapered coaxial balun with a dielectric was proposed for the UWB UHF coupler. The performance of the proposed balun was verified through a series of simulations, measurement and experiments. As results, both the conventional balun and the proposed balun of which length is one third of that of the conventional one showed good S11 characteristics, whereas the efficiency of the proposed balun increased as much as about 30% in comparison with the conventional one.