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.
Anguera, J. [et al.]. Dual frequency broad-band stacked microstrip antenna using a reactive loading and a fractal-shaped radiating edge. "IEEE antennas and wireless propagation letters", 02 Juliol 2007, vol. 6, p. 309-312.