On the Design of Millimetre Wave EBG Resonator Antenna Based on Woodpile Structure

Electromagnetic bandgap structures (EBG), also known as photonic bandgap structures (PBG) in optics, are now finding numerous applications in microwave and millimeter wave devices. In general, EBGs are periodic structures consisting of dielectric or metallic elements, and exhibit forbidden frequency bands (bandgap). In this paper, we present an EBG resonator antenna based on woodpile structure at millimeter frequencies. The dispersion characteristics of the woodpile structures have been analysed using 3D FDTD codes with a periodic boundary condition (PBC). We investigate the effect of design parameters including feeding structures, material parameters, period and dimensions of the EBG structure. The design of woodpile is based on alumina rods (epsiv_r = 9.6). Directivity patterns and side lobe levels will be presented. We also present the design considerations for EBG resonator antenna. The designed EBG antenna shows desirable directivities. At 93 GHz, directivity of 18 dBi has been achieved, which is approximately 11 dB improvement for the original antenna.