Study on the effect of radiation pattern on the field coverage in rectangular tunnel by fdtd method and point source array approximation

In this paper, the effect of radiation performance of antenna array in confined space on the field coverage is analyzed. In order to find the suitable radiation pattern that can give smoother wave coverage in confined space, a simple but efficient numerical method based on the parallel FDTD method and point source array approximation is presented. The current on each array element is obtained from the desired radiation pattern using synthesis method. This current distribution is then set to the FDTD mesh as the excitation. By this method, field coverage of three kinds of antennas with different radiation patterns in a rectangular tunnel is analyzed. The results show that the antenna with narrower beam width can give smoother field coverage in the tunnel.