Negative group delay experimentation with tee connector and cable structures Fayu Wan, Xiaoyu Huangi, Preeti Thakur, Atul Thakur, Sébastien Lalléchère and Blaise Ravelo Eur. Phys. J. Appl. Phys., 91 1 (2020) 10903 Published online: 30 July 2020 DOI: 10.1051/epjap/2020200016