当两个具有高功率电平的干扰信号混频时便产生一个不希望的中频（IF）信号，此信号称之为三阶分量。当这种情况发生时就有可能检测不到所希望的信号，干扰信号的组合会导致信号降低。此问题称之为互调失真（IMD）。IMD的起因是接收机某些级中器件的不可避免的非线性行为。量度 When two interfering signals with high power levels are mixed, an unwanted intermediate frequency (IF) signal is produced. This signal is referred to as the third-order component. When this happens it is possible that the desired signal will not be detected and the combination of interfering signals will result in a signal degradation. This problem is called intermodulation distortion (IMD). The cause of IMD is the unavoidable non-linear behavior of devices in certain stages of the receiver. Measurement