An antenna for radiating an electromagnetic field having both linear and circular polarization includes a ground plane and a dielectric layer. The dielectric layer is disposed on the ground plane and has at least one exposed surface that radiates the electromagnetic field. A first feeding element is disposed on the exposed surface for electrically exciting the dielectric layer to provide the linear polarization at a first frequency having a first effective wavelength. A second feeding element is disposed on the exposed surface for electrically exciting the dielectric layer to provide the circular polarization at a second frequency having a second effective wavelength. The feeding elements are separated by a distance greater than ⅛ wavelength of the largest of the effective wavelengths.