Abstract
This study aims to improve the directivity of coupled antennas for microwave heating of asphalt mixture. For this purpose, the total electric fields radiated by two antennas were modeled on H & E-planes, the antenna radiation power densities on H & E-planes were explored, and the directivity factor models of coupled antennas on H & E-planes were established. Analysis of the relationship between the directivity factor on H & E-planes, the gap between adjacent horn antennas, the structure parameters of horn antennas reveals that the directivity factor is increased with an increase in the horn length inside H& E-planes, begins to increase and then shows a downward trend after reaching the peak with an increase in aperture length, and is reduced with an enlargement of the antenna gap. Based on the findings, recommended values for the configuration parameters of the microwave heating antenna, including optimum length, optimum aperture size, and optimum gap size of the antenna array, were suggested to increase electromagnetic field distribution uniformity.