Patent attributes
An antenna apparatus has a ground plane and a traveling-wave linear antenna The ground plane has a dielectric layer and metallic plates disposed on the dielectric layer. The plates placed on a front side of the ground plane act as a band gap surface. The dielectric constant and thickness of the dielectric layer, the number of plates and the width of spaces among the plates are adjusted, so that the band gap surface prevents propagation of electromagnetic waves within a specific frequency band. The antenna is disposed over the band gap surface on the front side of the ground plane to be spaced away from the band gap surface. The antenna radiates electromagnetic waves of an operational frequency within the specific frequency band in response to an alternating current of the operational frequency fed to the linear antenna.
