Design of broadband transpolarizing surfaces

A transpolarizing reflector is proposed. It consists of periodic patches above a ground plane, with wide diagonal slots. For normal incidence, linear polarization along a principal direction is transformed into the orthogonal polarization with a 20-dB ratio over a 29.7% bandwidth. We prove that, in view of the diagonal symmetry of the structure, reflected fields in the principal directions must be in quadrature. The transpolarization bandwidth slowly decreases for incidence away from broadside. This surface very efficiently produces polarization conversion for circularly polarized incident fields. The quality of this conversion, described in terms of axial ratio, is obtained front the transpolarization level achieved in the linear polarization case. (c) 2006 Wiley Periodicals, Inc.