© 2018 IEEE. With the high penetration of power electronic interfaces and the increased use of power line carrier communication, high frequency (HF) emissions (supraharmonics) in the range of 2-150 kHz are emerging as a new power quality issue in distribution networks. Both IEC 61000-4-7 and IEC 61000-4-30 recommend the use of a high pass (HP) filter during measurement/analysis of these emissions. However, the filters used so far in HF measurements have non-linear phase characteristics making phase details unsuitable for further analysis. As a solution, this paper proposes a digital, offline, zero-phase HP filter having near ideal magnitude characteristics and a zero phase response.