Design and simulation of Phononic Crystals (PnCs) with a wide Acoustic Band Gap (ABG) around 1 GHz is presented. A new PnC unit cell topology is designed, which has a very wide ABG of 138 MHz with center frequency around 1 GHz and minimum feature size of 0.6 μm. Wider ABG allows better enhancement of the Quality factor (Q) by reducing the anchor loss. Effect of geometrical variation and the periodicity of PnC are discussed. ABG for 1D and 2D periodicity is simulated and geometrical dimensions to obtain similar ABG in both cases are compared. © 2019 IEEE.