Suppression of Multiple Reflection by Metasurface Absorber in 120-GHz-band Close-Proximity Wireless Link

We investigated a metasurface absorber integrated planar slot antenna for a 120-GHz-band close proximity wireless link. We adopted the split-ring resonators (SRRs) made by TaN on a quartz substrate for the metasurface absorber, and the measured S 11 of the absorber at 125 GHz is 17 dB. We simulated the transmission characteristics of the close proximity wireless system using these absorber integrated planar slot antennas. The simulated fluctuation of S21 in the 120-130 GHz band is below 4 dB, and the delayed waves that comes from the multiple reflection between Tx and Rx antenna was suppressed.