The Propagation Model of Modulated Subterahertz Signals in the RoF Communication Systems

Radio-over-Fiber system scheme is described in the paper, the radio domain of this system is performed in the range 75–110 GHz (W-band). Optical signal with given orbital angular momentum (OAM signal) generation method in RoF fiber optic domain is suggested. The method is based on applying two independent lasers, performing at close wavelengths and the device for spatial phase modulation. For simulation and system parameters calculating, mathematical model of OAM signal envelope is suggested based on simplified wave equations system. Computer simulation of these signals envelope during its transmission was performed. It is shown that distortion of transmitted signals arises because of wavelengths difference. Recommendations were developed for constructing fiber-optic components of the system (including a radio-optical converter) designed to minimize this distortion.