Analysis and design of a two-octave polarization rotator for microwave frequency

The analysis and design of a 45 degrees polarization rotator are presented. A two-octave frequency band is achieved with only three grids of strips, each rotated with respect to the previous one. Over this band the transmission loss is less than 0.5 dB, the circular polarization ratio is less than 2.0 dB, and the major axis of the polarization ellipse forms 45 degrees +or-3 degrees with respect to the linear polarization direction of the incident plane wave. The analysis method is an original scheme based upon the conjugate-gradient fast Fourier transform (CG-FFT) method to analyze periodic structures and the generalized scattering matrix method to study their connection. A comparison between numerical and measured data is presented.<
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