DOA Measurement of 300-GHz-band Signal Propagation through Tree

This paper presents the results of a measurement of the direction of arrival (DOA) of 300 GHz signals diffracted and reflected by trees using a high-speed terahertz hemispheric scanner. The shadowing loss by a trunk with a diameter of 10 cm is approximately 15 dB, and that of a tree with dense leaves and thin branches was about 25 dB. DOA measurement results revealed that the density of thin branches and leaves has a great impact on DOA spread.