Broadband EBG Structures with Compact Unit Cell

The design of a hook-like EBG structure with a small unit cell size is presented in this paper. This hook-like structure has a high inductance of the equivalent electrical LC-circuit, which enables the realization of broadband band-gaps at very low center frequencies. Simulation and measurements show, that the novel structure improves the relative bandwidth by 77% and lattice size by 59% compared to the standard mushroom-like EBG structure. In addition, a second EBG structure with a relative bandwidth of 15% is presented, which is generated with the aid of a genetic algorithm (GA). Measurement results of the proposed designs show good agreement with simulation.