A novel electrical gating circuit is proposed for ultrafast applications in electronics. The circuit employs a two-conductor coupled line, and does not have any active devices such as transistors or diodes. Hence, the ultimate speed of the circuit is limited only by the cutoff frequency of the lines employed. The authors describe the circuit theory and discuss the results of experiments that involved ultrafast measurement using electro-optic sampling techniques. The latter suggests the potential of the circuit to achieve the gatings of at least 80-Gbit/s.