Theory of antenna radiation from photonic band-gap materials

A unified formulation of antenna radiation from photonic band-gap (PBG) mat erials is described in this paper. An analytical array scanning method is a pplied to formulate the boundary-value problem associated with source inter action with infinite periodic structures. A double vector-integral equation formulation in conjunction with multi-stage moment methods is introduced t o characterize the current distribution over antenna elements, the near fie lds, and associated circuit parameters of interest. Asymptotic method is us ed to find the far-zone radiated waves and the periodic guided waves, which are used subsequently to determine the antenna radiation characteristics i ncluding gain (directivity) patterns, efficiency, and periodic guided wave power pattern. Of particular interest is the photonic bandgap effect to the periodic guided waves. Potential high-gain surface wave antenna using a PE G substrate is also discussed.