Radio Frequency Electromagnetic Field Exposure of Insects at 10 cm From an Antenna

The increased exposure of insects to radio frequency electromagnetic fields (RF-EMFs) may have an impact on their health. The RF-EMF absorbed power in certain insects is considerably higher in the range of 6 GHz to 300 GHz, due to more comparable wavelengths to their size. Likewise, in this range, the near-field interactions between antennas' and certain insects can significantly affect antennas' performance. Thus, in this work, the volume and frequency dependencies of the RF-EMF absorbed power in various insects is evaluated in the range of 6 GHz to 120 GHz, at a fixed separation distance of 10 cm between the insects and a dipole antenna. Moreover, the effect of these insects on the dipoles' performance is assessed. To this aim, numerical simulations using finite-difference time-domain (FDTD) were performed on insect models obtained through micro-CT scanning. These simulation results showed an average absorbed power of 3.1 $\pm$ 2.7 mW/W at 6 GHz and of 3.4 $\pm$ 2.8 mW/W at 120 GHz. Also, they revealed that the absorbed power increases with increasing insect volume at an approximate rate of $\text{2.5}\:{\mu \text{W}}/{\text{W}\cdot \text{mm}^{3}}$ at 6 GHz, and of $\text{1.2}\:{\mu \text{W}}/{\text{W}\cdot \text{mm}^{3}}$ at 120 GHz, and that this rate of increase lowers with increasing frequency. Furthermore, results showed that the dipoles' gain pattern have a dependency on the insects' volume with a stronger dependency for higher frequencies.