A partially filled substrate for a rectangular patch antenna

In this paper, the design, modeling and simulation of a partially filled substrate for a rectangular patch antenna is presented. The effect of a piece of a magnetic part on the substrate of the patch antenna is investigated. It is shown that the return-loss, the number and frequency of excited modes and consequently the bandwidth of antenna are a function of the place of this magnetic part in the substrate. Then, presenting a lumped-element model for the antenna, it is tried to explain this phenomenon, regarding the role of the magnetic part in changing the elements of the model. Finally, a rule for the relationship between the model elements and the percentage of the filled area under patch, which in fact shows the place of magnetic part, is found. This rule is used as a procedure to design an antenna with a higher bandwidth of more than 10%.