Performance of a phase switched screen against a pulse compression radar system

In conventional microwave absorbent materials, the incident electromagnetic energy is absorbed and converted into heat. An alternative technique for achieving an apparent reduction in the level of the electromagnetic energy reflected from a surface uses the so-called "phase switched screen" (PSS). At resonance, the ideal single layer PSS presents a periodic reflection coefficient, ρ(t) = ±1, to an electromagnetic wave incident on its surface in such a way that the time-averaged value of ρ(t) is zero. This is equivalent to applying binary phase modulation to the reflected wave, with the result that the energy is redistributed into sidebands with, ideally, none remaining at the original carrier frequency, f_c. Hence, by adjusting the frequency of the waveform that controls the surface reflection coefficient, these sidebands may be positioned so that they lie outside the pass-band of a receiver tuned to f_c. We describe a MATLAB^® and Simulink^® software package, PSSim, which can be used to demonstrate the operation of a PSS in the presence of signals from generic pulse and pulse compression radars.