Compact wideband stacked microstrip patch antenna for a medical application

Use of larger dielectric constant in the substrate of microstrip patch antenna can significantly reduce the antenna size. However, it also decreases impedance bandwidth. On the other hand, stacked patch antennas are known to exhibit wider bandwidth than their predecessors, traditional single patch. An impedance bandwidth enhancement of 45% is achieved using stacked microstrip patch antenna. This much bandwidth enhancement suffices in some applications, including the medical one which initiated this work.