A coupling model for the waves in ion cyclotron resonance frequency (ICRF) in tokamak plasmas is described. The simulation is performed based on the finite element method. A cold plasma dielectric tensor is used. A perfectly matched layer (PML) is applied to describe the ICRF wave single-pass absorption in the core plasma. The selection of PML characteristic parameters is optimized in a wide wave frequency range and validated for plane waves and ICRF waves. The dependencies of the coupling resistance on the plasma-antenna gap, average plasma density, and plasma profiles are given. The simulation results are in good agreement with the experimental results.