The non-ideality of payload channel can cause the navigation signal distortions,which would lead to the performance degradation.The distortions due to non-ideal channel fall into the linear and nonlinear signal distortions.The linear distortion is usually introduced by filter and triplexer,and non-linear distortion mainly depends on high power amplifier.Analyzing the non-ideal characteristics of channel is helpful to optimize the navigation payload design and improve the navigation signal quality.