Miniaturization of Slot Antennas Using Wire Loading

The design of a miniaturized slot antenna based on wire-loading is presented. The miniaturization can be achieved with minimal increase in the lateral space along the slot width. Both the cases of a slot antenna on dielectric substrate and a slot antenna on ground plane are considered. For the former case, a miniaturization of 28.83% is achieved. The radiation characteristics of the size-reduced antenna are almost similar to the unloaded slot, with low cross-polarization levels. For the slot antenna on a ground plane, the miniaturization is affected by a cavity-backed design with the loading wires penetrated into the cavity. A 45.52% reduction in resonant frequency is achieved relative to the unloaded slot. The radiation characteristics in the upper hemisphere are almost unperturbed compared to the unloaded slot.