Realization concepts for compact microstrip antennas with periodically loaded lines

The possibility to develop compact microstrip antennas employing the concept of periodically loaded lines is demonstrated and three different realization possibilities are presented. A basic electrical model is proposed, which allows the bandwidth estimation in dependence of geometrical and material parameters. Data from full wave electromagnetic simulation and measurement of the fabricated demonstrators is compared with this model, giving an impression of the applicability and the achieved accuracy. Based on the model, parametrical studies have been performed allowing an outlook on obtainable bandwidth-limits of the structures. Additionally efficiency and gain values are determined and their correlation to the substrate height is extracted.