Oblique incidence reflectivity characteristics of planar phase-switched screens

The reflectivity characteristics of planar phased switched screens (PSS) at oblique incidence have been examined and compared to those of conventional passive absorbers. A single layer PSS shows similar characteristics to that of a Salisbury screen, but has the advantage that at oblique incidence simultaneous TE and TM performance may be obtained by the correct choice of modulating waveform. An active two-layer PSS shows increased bandwidth and has the additional advantage of the ability to dynamically steer the reflectivity nulls in response to changes in both the frequency and angle of illumination. Measured data from an experimental two-layer PSS have been presented to demonstrate reflectivity null steering over a wide band of frequencies at both normal and oblique incidence.