Research on the Dual Antennas System for Directional Transmitting

The radio covering area in band shape could be produced by dual antennas system for directional transmitting (DASDT), which transmits radio signals in the same phase by two antennas. DASDT is a kind of transmitter that is compatible with the radio covering channel in band shape, and it could be applied in the environment of common radio covering channel in band shape, such as corridors, highways and railway. Under the conditions of the two signals fed to the dual antennas being in phase and the distance between those two antennas is λ/2, where λ is the wave length of the radio frequency, the mathematical equations for directional beam-forming could be deduced, and then the physical mode could also be derived. Many simulation results of beam patterns are given in this paper, and they could be used to confirm the effectiveness of the DASDT system for the directional beam-forming.