Measured Blockage Effect of a Finger and Similar Small Objects at 300 GHz

We study the effect of a finger, and other objects with similar shape, on the channel gain in short distance propagation measurements at 220—330 GHz. Channel impulse responses and channel gains of six objects are analyzed on different positions obstructing a 35 cm line of sight (LOS) link. The intention is to evaluate potential user effects on portable devices supporting the future 6G system. Very short wavelength and link distance cause strong fluctuation of channel gain even on millimetre scale movement of obstacles. The finger phantom causes 44 dB attenuation on close vicinity, 5 mm, of transmitter antenna and has similar attenuation pattern with corresponding metallic stripes. On the contrary, it is observed that some objects, such as the measured Nylon rod, may even increase the signal strength. These impacts are important when studying the wave propagation and network aspects of high frequencies systems.