Planar band-notched ultra-wideband monopole antenna using single open-circuited stub

This paper presents a novel printed monopole antenna with band-notched characteristics. The proposed antenna consists of a sector radiating monopole and a microstrip feedline connected in shunt a quarter wavelength open-circuited stub. In order to achieve band-notched performance, using a single open-circuited transmission line (a stub) of length quarter wavelength, connected in parallel with the microstrip feedline at a certain distance from the monopole antenna. The input impedance of the quarter wavelength open-circuited stub is nearly zero impedance leads to the great reflection and impedance mismatching at the notch frequency, which causes the antenna to be nonresponsive and occurs band-notched phenomenon. This design technique is very suitable for other printed antennas.