Unified jet-DBD design, [Formula: see text], proposed in this work presents large-scale plasma in an unbounded region of atmospheric air, without any need for the flow of gas, offering efficient exposure to sizable and complex objects. This is a simulation-based architecture for stable non-thermal plasma source with notable experimental results. [Formula: see text] geometry optimizes the electric field and charge distribution for a diffuse discharge in the steady air by a key design parameter of [Formula: see text]. Teflon insulator with a thickness [Formula: see text] imposes an intense and uniform electric field shaped up at the open area in front of the device and generates radially/axially expanded plasma jet. In the [Formula: see text], phase shift increases by [Formula: see text] and the plasma generates more power than the classical plasma jet. Two distinct states of [Formula: see text] operation indicate the mode-swap at [Formula: see text] and power dissipation. In the reactive [Formula: see text] scheme even small changes in the phase angle effectively improves the electric power.