Nonthermal plasma at atmospheric pressure can be produced in dielectric barrier discharges (DBDs), which are usually driven by AC power sources generating periodic sine or square pulses. Nanosecond-pulse DBDs driven by pulsed power sources can also be used to produce the nonthermal plasma. Different results are obtained, however, by employing different pulsed power sources and DBD configurations. In this entry, some compact pulsed power sources are described. Firstly, high-voltage switches used for pulsed power sources are presented, and then two main technical methods including pulse superposition and pulse compression are given in this entry. Finally, some characteristics of nanosecond-pulse DBDs driven by compact nanosecond-pulse generators are presented. It is found that, compared with AC excitation, DBDs produced by unipolar nanosecond pulses can result in a more homogeneous discharge mode.