Switchable Polarization Conversion Using Reflective Electromagnetic Surfaces in mmWave Spectrum

In this paper, the design of a wideband switchable polarization conversion (SPC) is proposed by utilizing Reflective Electromagnetic Surfaces (RES) to operate in millimeter-wave (mmWave) spectrum. The SPC or polarizer which aims to work at two-state conditions comprises an infinite array of square patch unit cell in two-dimensional arrangement on an FR4 epoxy dielectric substrate. In the OFF-state condition, the proposed RES works as a polarizer, changing the linear polarization of incident waves into the circular polarization of reflected waves in the frequency range of 16 GHz to 25.5 GHz. Whilst in the ON-state condition, the RES functions as a regular reflector in the same frequency range. Characterizations using oblique incident waves show the influence of incident waves angle on the bandwidth response of RES as a polarizer. For every 10° increase in the angle of incident waves, the bandwidth response of polarizer decreases by about 5%.