Patent ID: 8289220

Claim:
A periodic structure reflector plate, comprising: a structure in which structures each for controlling a reflection angle by controlling a phase difference of reflected waves are periodically arranged, wherein in n reflector plate constituent pieces r k (1â‰¦kâ‰¦n) arranged at intervals of Î”S k , when a phase of reflected wave in each reflector plate constituent piece r k is Î¦ k , a phase difference (Î¦ k+1 âˆ’Î¦ k ) between each reflector plate constituent piece r k and an adjacent reflector plate constituent piece r k+1 is Î”Î¦ k , and wavelength of the reflected wave is Î», a plurality of blocks are provided for every period T (Tâ‰§RL), each of the blocks being formed of the n reflector plate constituent pieces r k that are arranged to satisfy an expression #1 â€œÎ±=sin âˆ’1 (Î»Â·Î”Î¦ k /2Î Â·Î”S k )â€ for an angle Î± indicative of a traveling direction of desired reflected wave, each of the blocks having a length RL specified by: R â¢ â¢ L = âˆ‘ K = 1 n â¢ Î” â¢ â¢ S k .