The relation of the power reflection coefficient in tokamak plasma surface and absorption attenuation of the ion cyclotron wave to the emission spectrum n|| of ICRH antenna is studied by using a stratified plasma slab and the WKB approximation. The effect of fast wave minority ion heating in different emission spectrum conditions of ICRH antenna is numerical calculated. The simulation results show that under the same conditions, the coupling efficiency of the antenna with the plasma and the effect of fast wave minority ions heating ...