Common RF absorbers evaluations in W-band (75-100 GHz)

This article consists of a collection of slides from the author's conference presentation. Conventional commercial polyurethane absorbers when optimized can achieve about 35-40 dB reflectivity in W band. Latex paint can degrade the absorber performance. Black tips do not significantly improve the performance. Best absorbers are convoluted absorbers (egg crate shaped). Second best are the 3” or 5” pyramids. Flat absorbers with optimized loading can achieve ~30 dB reflectivity in the W band. Wave can penetrate into the absorbers 1” deep. EMC hybrid absorbers generally can only achieve 20 dB reflectivity.