Circular-to-linear polarization converter based on composite via-coupled patch frequency selective surfaces

In this paper, we present a design of circular-to-linear polarization converter operating in C-band based on a composite frequency selective surface which consists of two types of via-coupled patch modules. The building unit cell is built with four modules, and each one is a truncated patch pair printed on the double-layer substrate and vertically connected by a metal via-hole. A perforated common ground plane is sandwiched between the double layers to support transverse electric and magnetic mode coupling between the front and back patches. The front diagonally truncated patch array responds to the incident right-handed circularly polarized wave, and it is identically converted into general right- and left-handed elliptically or circularly polarized waves with same phase shifts, amplitudes and axial ratio, thus a resultant linear polarized wave is generated in forward transmission mode.