Accession Number:



Effects of Variable Spot Size on Human Exposure to 95-GHz Millimeter Wave Energy

Descriptive Note:

[Technical Report, Interim Report]

Corporate Author:

711 Human Performance Wing

Report Date:


Pagination or Media Count:



The report documents two studies that were conducted to quantify human behavioral responses to 95-GHz millimeter wave MMWexposures employing differing beam sizes and power densities. Previously, the speed of the repel response was found to be dependent upon the power density and spot size on the target, but the exact form of this function was unclear. To provide clarity of the repel effect function, we investigated two experimental paradigms. Experiment 1 examined the repel times of stationary subjects at combinations of three MMW power densities and five spot sizes. Experiment 1 results confirmed that repel times decreased within creasing beam size, although the strength of this relationship varied with power density. Experiment 2 investigated the extent to which the Experiment 1 relationships between beam size and repel time could be extrapolated to moving subjects. Subjects were required to throw balls into a net while being targeted by the MMW beam. Results indicated similar performance at the four largest spot sizes tested, and better subject activity performance i.e., decreased MMW effectiveness at the smallest spot size.

Subject Categories:

  • Defense Systems
  • Weapons Effects (Biological)
  • Radiofrequency Wave Propagation

Distribution Statement:

[A, Approved For Public Release]