Cylindrical high impedance surface (HIS) structures and their E-plane omnidirectional antenna application are presented at the 2.0 GHz band. The diameter of the cylinder is 39.2 mm, when the ϕ-direction periodicity is chosen as three. The HIS, when illuminated by plane waves, not only reflects them in the direction of arrival with zero phase, but also transmits them in other directions to a comparable degree, which is caused by half-wavelength resonance of all of the patches. A dipole antenna element situated close to the HIS, the ϕ-direction periodicity of which is three, exhibits VSWR = 1.5 and an omnidirectional Eplane pattern at 2.14 GHz.