Compact dual-frequency operation of rectangular microstrip antennas

The present article proposes two promising compact dual-frequency antenna designs with four narrow slots or four T-shaped slots. The proposed designs have been successfully implemented. The two operating frequencies can easily be controlled by the aspect ratio of the rectangular patch and the slot size embedded in the patch. Results also indicate that the two proposed designs can have a larger antenna size reduction for a fixed dual-frequency operation than the compact dual-frequency designs shown in Wong and Yang (1997, 1998).