Hybrid mode radiation in patch antenna loaded with corrugated electric via arrays

A dual band patch antenna is implemented by introducing perfect electric conductor (PEC) boundary conditions using electric via arrays between the patch and the ground in a corrugation pattern. By appropriately designing the via array profile, non-Bragg resonance occurs and a hybrid electromagnetic (EM) mode which is caused by interaction between adjacent transverse EM modes takes place. Higher mode EM radiation is also activated. In this work, two sinusoidal via arrays with a period of 34.6mm, an amplitude of 6mm are fabricated between the patch and the ground, where the dimensions of the patch is 44mm × 32.4mm. The structure is excited with TE10 mode. However, radiation only occurs at a hybrid mode at 6.8GHz and TE₂₀ mode which is 7.3GHz, and thus the proposed structure is working as a mode shifter. Both theoretical derivation, numerical simulation and measurements show good agreement, the proposed structure can be used as a dual band patch antenna as well as EM mode shifter that could excite higher EM modes and suppress fundamental EM modes.