Dual-Frequency Broadband-Stacked Microstrip Antenna Using a Reactive Loading and a Fractal-Shaped Radiating Edge

A dual-band enhanced-bandwidth microstrip antenna is presented with a frequency separation of f2/f1=1.37. In order to achieve the dual-frequency operation, a rectangular patch antenna is reactively loaded with a stub placed along one of the radiating edges. Then, the bandwidth is enhanced using a stacked parasitic technique, whereas the matching and radiation characteristics are kept constant along each band and similar at two bands.