In this work, the study of the microwave noise performance for InGaAs/InP composite channel HEMT compared to InGaAs channel is performed. Detailed microwave noise characteristics of InP-based HEMT are presented. An interesting observation is that the minimum noise figure (NF/sub min/) in composite channel devices is insensitive to drain bias, which is different from the conventional single channel devices in which the minimum noise figure increases with the increase of the bias. An analytical model was provided to study the channel noise for both devices and verify the influence of the different channel structure on the noise performance.