A Conformal Band-Notched Ultrawideband Antenna With Monopole-Like Radiation Characteristics

A conformal, planar, and low-profile ultrawideband antenna with monopole-like radiation and band-notched characteristics is presented. A circular patch shorted to the ground is combined with two rectangular slots and two concentric rings, to achieve an ultrawide bandwidth from 3.8 to 8.3 GHz with a single rejection band from 5 to 6 GHz. The monopole-like radiation features, generated by combining TM $_{01}$ and TM $_{02}$ operating modes of a circular patch antenna, are maintained over the entire operating bandwidth. The antenna has only 0.046 $\lambda _{o}$ height at 3.8 GHz and is realized using polydimethylsiloxane conductive fabric composite technology making it highly flexible and physically robust. This was validated through severe bending tests with various curvatures.