Patent attributes
A composite polarizer including a first polarizer having a plurality of parallel metal vanes and a second polarizer having a plurality of parallel layers of dielectric material is provided. The first polarizer is disposed on an axis, and has a phase advance orientation orthogonal to the axis. The second polarizer is disposed on the axis and has a phase advance orientation orthogonal to the axis. The first polarizer has a first differential phase shift for a first frequency f1 and a second differential phase shift for a second frequency f2. The second polarizer has a first differential phase shift for the first frequency f1 and a second differential phase shift for the second frequency f2. A total of the first differential phase shifts of the first and second polarizers is about 90°, and a total of the second differential phase shifts of the first and second polarizers is about 90°.
