Planar printed self-cancelling scatterer

The first experimental evaluation of a microstrip self-cancelling scatterer or 'anechoic reflector' under linear and circularly polarised excitation is described. Monostatic radar cross-section (MRCS) measurements of the signal reflected back from the device are shown and these are compared with the theoretical MRCS predictions. The resulting circuit measuring 44 x 44 x 0.254 mm (W x H x D) operates at 10.2 GHz and yields up to -32 dB reduction in return signal at boresight relative to a flat metal sheet having the same dimensions for incident linear polarisation. The structure is also shown to re-radiate incident CP excitation.