Study on Homogenization Methods of Stacked Rectangular Dielectric Resonator Antennas

The effective dielectric constant (EDC) theory for stacked rectangular dielectric resonator antennas (DRAs) is investigated. First, the classical static capacitance models (SCMs) are revisited. It is found that these models might have been abused, e.g., controversial models were applied in similar structures. Accordingly, the accuracy of these EDC methods is questionable though they are widely used. To solve this problem, numerical experiments are conducted for validation. Novel homogenization methods are then introduced based on the effective medium theory as improvements. All the above methods are compared through a set of DRA samples where the resonant mode and stacking order are taken into account. The practicability of each method is then discussed based on error analysis. It is found that the effective medium theory outperforms the prevalent SCMs.