Simulation of interaction of antennas in the near zone

Abstract

Relevance. Obtaining the minimization or maximization of the interaction between the radiating and receiving antennas (or the receiving antenna with fields reflected from some obstacle) due to the orientation and location of the antennas at a certain distance and at certain angles is analyzed. Solving such problems will allow creating effective radio-electronic devices for various purposes, in particular, radar systems and information processing algorithms.

The purpose of the work is to carry out modeling of the pulsed radiation of a dipole antenna, determine the patterns of such radiation at different locations of the receiving antenna relative to the transmitting antenna. To determine the signal in the receiving antenna and identify the regularities of its formation.

Materials and methods. To solve the given problem, the Finite Difference Time Domain (FDTD) method was used with using the Yee algorithm for the numerical solution of Maxwell's equations. The spectra of the emitting and receiving antennas are analyzed using the Fast Fourier Transform (FFT) algorithm. The Near to Far Transformation algorithm is used to obtain antenna directional diagrams in the far zone.

Results. Received signals in time form for transmitting and receiving antennas. The analysis of the spectra obtained using FFT from the time forms of the signals in the transmitting and receiving antennas demonstrated that the signal spectrum for the radiating antenna contains components at low frequencies below 250 MHz, such components are not observed for the receiving antennas. The time dependence of the current in the antenna at each moment of time and the spectrum of the current were obtained, the directional diagram of the antenna in the far zone was obtained.

Conclusion. For receiving antennas located at a distance  from the radiating one, we have the largest component of the field at the frequency corresponding to the first resonance, this is especially significantly manifested in those located at angle , where the signal in other antennas (at a greater distance from the emitting one) is very small. For antennas located at a right angle, that is, for coaxial antennas, the energy transfer from the radiating antenna to the receiving antenna is maximal, but only at short distances, as the distance between the antennas increases, the connection between them quickly decreases.