A radio emission is divided into the zone near and far from the source, and TSU radiophysicists have learned to increase the near zone. This method can be used to create devices for radar and noninvasive diagnostics of human internal organs and various diseases. Scientists have developed a device for controlling the near-field radio emission, and the findings are presented in an article in the Journal of Applied Physics.
The border between the zone that is near the source and the zone that is far from it is quite sharp and is called a causal surface. Beyond this surface, a skin layer appears in which the radio wave attenuates very quickly (exponentially). As a rule, scientists investigate the far zone, because this is necessary to create antennas that work over long distances. They try to reduce the near zone because it does not bring noticeable benefits for communication and radar.
TSU radio physicists have established that radiation in the near field does not have exponential attenuation, which means that it can penetrate well into media with a high absorption coefficient, for example, into the human body. It is enough to expand the borders of the near zone, removing it from the source.