A band-notched UWB antenna with good shape factor

A microstrip antenna integrated with a frequency-controlled bandstop filter which is based on a second order filter is proposed in the paper. It works in the Fedral Comunication Commission (3.1-10.6GHz) with the notched band at the IEEE 802.11 standard for the frequency band of 5.15-5.85GHz. To do a description about the filtering capability of the notched-band antenna, a shape factor similar to that of a filter is placed to help to evaluate in the paper. The antenna can obtain an attenuation figure -3dB at the notched band, and its shape factor can achieve 0.72 as good as a filter. The antenna has adopted a multilayered structure to gain a good shape factor, but its manufacturing process is not complex for little vias to connect each layer. The antenna is fabricated with a shorted patch, mainly radiated patch and a ground jointed with two resonant stubs on a FR4-epoxy substrate. So its manufacturing costs are very cheap. The entire antenna can work as a wide band antenna with a bandstop filter which has a perfect rectangle coefficient.