QPSK reflector based on textured surface technology

In this paper, a suitably designed textured surface is numerically investigated to be applied as a quadrature phase-shift keying (QPSK) reflector. The proposed arrangement uses the form of an artificial magnetic conductor printed on a dielectric substrate with the incorporation of surface mounted electronically controlled elements onto the textured surface to control the phase of the surface in order to encode pi/2 phase differences. The investigation shows that by adjusting the surface capacitance of mounted active element to each of four possible different states the arrangement can generate four different phases of reflected signals thereby making the structure useful as a QPSK reflector. In addition, the effect of different thickness of a dielectric substrate is also investigated and the result is included for comparison.