The strip grating as a circular polarizer

A conducting strip grating can convert a linearly polarized plane wave into one that is circularly polarized. The conversion of a normally incident wave is most efficient when the grating period is 0.874 times the wavelength, the width of the strips is half the grating period and the angle between the direction of polarization and the strips is 45degrees. This result is confirmed by a microwave experiment at 35 GHz. (C) 2003 American Association of Physics Teachers.