Gain Enhancement of Printed Circuit Board Patch Antenna Using Electromagnetic Band Gap Structure

This paper presents a circularly polarized printed circuit board (PCB) patch antenna using mushroom-like electromagnetic band gap (EBG) structure for gain enhancement. Unlike the popular method of using artificial magnetic conductor (AMC) or EBG structure as the ground of the antenna, we place the mushroom-like EBG structure around the patch antenna to avoid increasing the number of PCB layers. The EBG structure works in-phase reflection around 24.25 GHz by optimizing design. Limited by the size of the antenna, only twelve EBG units can be distributed around the corner-cut square circularly polarized patch antenna. Simulation results show that gain of the antenna enhances 0.8 dB and cross polarized gain reduces about 15 dB, moreover, the axial ratio is also improved.