Combining two methods to enhance band-notch characteristic of ultra wide band antenna

In this paper, we combine two conventional stop-band creating methods to enhance band-notched function of a planar microstrip-fed monopole antenna with truncated ground plane. By combining a parasitic strip under the substrate and an inverted-U slot on the patch, a notch with two very sharp edges around 5.5 GHz WLAN band is obtained. The proposed antenna is fabricated on the substrate FR4 (relative permittivity of 4.7) and has a compact size of 16 × 30 × 1.6 mm. A good impedance matching is obtained in 3.1 -10.6 GHz frequency range, except the band 5.16 - 5.8 GHz and the radiation pattern is similar to the monopole antenna.