Design of two-cascade optical antenna for indoor visible light communication

White light emitting diode (LED) is expected to replace the incandescent lamp and becomes the next generation of lighting source because of its long life expectancy, high tolerance to humidity, and low power consumption. It is proposed that for the indoor visible light communication system white LED should be used as both lighting source and base station for its properties of high brightness and high speed modulation. Indoor visible light communication has a very wide area of applications, but there is a lack of research on receiver optical antenna that functions as an energy concentrator so as to increase received power. In order to meet the needs of high gain and meanwhile large field of view of receiver optical antenna for indoor visible light communication, two-cascade optical antenna is designed. It is shown that the field of view from 40 to 60 degrees can meet the requirements for high speed communication by analyzing the relationship between signal-to-noise ratio and data rate of different fields of view. The performances of the traditional optical antenna of Fresnel lens and the compound parabolic concentrator are simulated and analyzed by TacrePro. The gains of the designed two-cascade optical antenna are discussed at different incident angles. The results show that two-cascade optical antenna has better performance than traditional receiver optical antenna. The distribution of received power of two-cascade optical antenna is analyzed by using Matlab. The received average power by using two-cascade optical antenna is about 7 dBm larger than that without any optical antenna. The designed optical antenna provides a field of view of 40 degrees and enough gain for indoor visible light communication system.