Identification of V-band frequency-selective surface at 11 m standoff distance with a transceiver chipset

The authors demonstrate the detection of a millimetre wave frequency-selective surface with a null near 60 GHz at large standoff distances (≥10m) such as would be required for covert security labelling and anti-counterfeiting applications. The authors compare the performance of using lenses and offset parabolic reflector to improve the directivity of a commercial, compact, integrated chipset in a ball grid array package, finding a reduction in beam width from 60 to 5 and 10°, respectively. They measured the power spectrum of the system with no label at distances of 35 cm, 60 cm, 4 m and 11 m finding no appreciable fading effect with the higher-directivity system. The integrated system-measured response of the frequency-selective surface agreed well with that of a standard test set-up (horn antennas and vector network analyser) as well as numerical simulations conducted with a frequency-domain solver (HFSS).