PURPOSE: To obtain frequency selection mirror surface different from the direction of reflection by frequencies, by regularly providing grooves in pillar shape on a metallic plate and changing the parameter of the pillars.
CONSTITUTION: A frequency selection mirror surface consists of a metallic plate 1a and grooves 1b of prism shape made on the metallic plate. When the length of sides of metallic lattice is taken respectively as (a) and (b), the incident angle of plane waves is taken as θ0, and the mirror plane is placed so that the incident plane is in parallel with the side of (b) in length, then the electromagnetic waves λ2 in wavelength are reflected on the metallic plate 1a according to the incident direction 2 of waves, independently of the shape of grooves, by suitably selecting the values (a) and (b). That is, the electromagnetic waves in λ2 are not entered the grooves, resulting that the grooved metallic plate 1a is equivalently regarded as a plane reflection plate to the waves in λ2. Thus, the degree of freedom can be given to the direction of reflection by changing the slope of the metallic plate, allowing to reflect the electromagnetic waves in shorter wavelength to be reflected on the shape of grooves.
HONMA YOSHIHIRO
MANO SEIJI
