Elliptical planar monopole antenna with extremely wide bandwidth

A planar monopole antenna with an extremely wide bandwidth is introduced, which is composed of an elliptical monopole patch and a trapeziform ground plane, both printed on the same side of a substrate, and is fed by a tapered CPW feeder in the middle of the ground plane. The simulated and experimental results demonstrate that this antenna achieves a ratio impedance bandwidth of 21.6:1 for VSWR≤2, and exhibits a nearly omnidirectional radiation pattern, while its area is only about 0.19λ_l×0.16λ_l where λ_l is the wavelength of the lowest operating frequency.