Assessment for the Radio Frequency Exposure Worst Case of Multiple Antennas Based on Particle Swarm Optimization

Exposure to RF electromagnetic fields does not cause safety problems only if the radiation intensity is below the values specified in the relevant regulatory guidelines. In this paper, we provide a method to determine the maximum radiation upper limit for multiple antennas. Valuing the upper limit of MIMO antenna radiation is considered as an optimization problem. Particle swarm optimization algorithm is used to search the complex weight of each antenna unit, and then the electric field is superposed according to the complex weight to solve the vector sum of MIMO electric field in space, and then SAR is evaluated Based on the above theory, the MIMO array composed of four antennas with three bands is constructed for smart helmet. The maximum specific absorption of MIMO antenna in Sam head is calculated by PSO algorithm and compared with Monte Carlo algorithm. The results show that the radiation can be obtained quickly by PSO algorithm. Combined with beamforming technology, this technique promises to optimize the overall performance and reduce the peak spatial specific absorption rate of MIMO wireless systems in the future.